[LSC] Replace base::string16 with std::u16string in //components

This change replaces base::string16 with std::u16string in //components.

Reproduction steps:
$ git grep -lw 'base::string16' components | \
      xargs sed -i 's/\bbase::string16\b/std::u16string/g'
$ git cl format

Bug: 1184339
Change-Id: Ifd99bc43ca04810a480466369b5cd6680bbe89ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2752068
Commit-Queue: Jan Wilken Dörrie <[email protected]>
Owners-Override: Peter Kasting <[email protected]>
Reviewed-by: Peter Kasting <[email protected]>
Cr-Commit-Position: refs/heads/master@{#862035}
diff --git a/components/javascript_dialogs/android/app_modal_dialog_view_android.cc b/components/javascript_dialogs/android/app_modal_dialog_view_android.cc
index 0cf60dc..9122c931 100644
--- a/components/javascript_dialogs/android/app_modal_dialog_view_android.cc
+++ b/components/javascript_dialogs/android/app_modal_dialog_view_android.cc
@@ -102,7 +102,7 @@
 }
 
 void AppModalDialogViewAndroid::AcceptAppModalDialog() {
-  base::string16 prompt_text;
+  std::u16string prompt_text;
   controller_->OnAccept(prompt_text, false);
   delete this;
 }
@@ -112,7 +112,7 @@
     const JavaParamRef<jobject>&,
     const JavaParamRef<jstring>& prompt,
     bool should_suppress_js_dialogs) {
-  base::string16 prompt_text =
+  std::u16string prompt_text =
       base::android::ConvertJavaStringToUTF16(env, prompt);
   controller_->OnAccept(prompt_text, should_suppress_js_dialogs);
   delete this;
diff --git a/components/javascript_dialogs/android/tab_modal_dialog_view_android.cc b/components/javascript_dialogs/android/tab_modal_dialog_view_android.cc
index 1e0785c..3d551200 100644
--- a/components/javascript_dialogs/android/tab_modal_dialog_view_android.cc
+++ b/components/javascript_dialogs/android/tab_modal_dialog_view_android.cc
@@ -27,10 +27,10 @@
 base::WeakPtr<TabModalDialogViewAndroid> TabModalDialogViewAndroid::Create(
     content::WebContents* parent_web_contents,
     content::WebContents* alerting_web_contents,
-    const base::string16& title,
+    const std::u16string& title,
     content::JavaScriptDialogType dialog_type,
-    const base::string16& message_text,
-    const base::string16& default_prompt_text,
+    const std::u16string& message_text,
+    const std::u16string& default_prompt_text,
     content::JavaScriptDialogManager::DialogClosedCallback
         callback_on_button_clicked,
     base::OnceClosure callback_on_cancelled) {
@@ -57,7 +57,7 @@
   delete this;
 }
 
-base::string16 TabModalDialogViewAndroid::GetUserInput() {
+std::u16string TabModalDialogViewAndroid::GetUserInput() {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jstring> prompt =
       Java_JavascriptTabModalDialog_getUserInput(env, dialog_jobject_);
@@ -68,7 +68,7 @@
                                        const JavaParamRef<jobject>&,
                                        const JavaParamRef<jstring>& prompt) {
   if (callback_on_button_clicked_) {
-    base::string16 prompt_text =
+    std::u16string prompt_text =
         base::android::ConvertJavaStringToUTF16(env, prompt);
     std::move(callback_on_button_clicked_).Run(true, prompt_text);
   }
@@ -80,7 +80,7 @@
                                        jboolean button_clicked) {
   if (button_clicked) {
     if (callback_on_button_clicked_) {
-      std::move(callback_on_button_clicked_).Run(false, base::string16());
+      std::move(callback_on_button_clicked_).Run(false, std::u16string());
     }
   } else if (callback_on_cancelled_) {
     std::move(callback_on_cancelled_).Run();
@@ -91,10 +91,10 @@
 TabModalDialogViewAndroid::TabModalDialogViewAndroid(
     content::WebContents* parent_web_contents,
     content::WebContents* alerting_web_contents,
-    const base::string16& title,
+    const std::u16string& title,
     content::JavaScriptDialogType dialog_type,
-    const base::string16& message_text,
-    const base::string16& default_prompt_text,
+    const std::u16string& message_text,
+    const std::u16string& default_prompt_text,
     content::JavaScriptDialogManager::DialogClosedCallback
         callback_on_button_clicked,
     base::OnceClosure callback_on_cancelled)
diff --git a/components/javascript_dialogs/android/tab_modal_dialog_view_android.h b/components/javascript_dialogs/android/tab_modal_dialog_view_android.h
index 681f9a1..a0aa249 100644
--- a/components/javascript_dialogs/android/tab_modal_dialog_view_android.h
+++ b/components/javascript_dialogs/android/tab_modal_dialog_view_android.h
@@ -27,17 +27,17 @@
   static base::WeakPtr<TabModalDialogViewAndroid> Create(
       content::WebContents* parent_web_contents,
       content::WebContents* alerting_web_contents,
-      const base::string16& title,
+      const std::u16string& title,
       content::JavaScriptDialogType dialog_type,
-      const base::string16& message_text,
-      const base::string16& default_prompt_text,
+      const std::u16string& message_text,
+      const std::u16string& default_prompt_text,
       content::JavaScriptDialogManager::DialogClosedCallback
           callback_on_button_clicked,
       base::OnceClosure callback_on_cancelled);
 
   // TabModalDialogView:
   void CloseDialogWithoutCallback() override;
-  base::string16 GetUserInput() override;
+  std::u16string GetUserInput() override;
 
   void Accept(JNIEnv* env,
               const base::android::JavaParamRef<jobject>&,
@@ -50,10 +50,10 @@
   TabModalDialogViewAndroid(
       content::WebContents* parent_web_contents,
       content::WebContents* alerting_web_contents,
-      const base::string16& title,
+      const std::u16string& title,
       content::JavaScriptDialogType dialog_type,
-      const base::string16& message_text,
-      const base::string16& default_prompt_text,
+      const std::u16string& message_text,
+      const std::u16string& default_prompt_text,
       content::JavaScriptDialogManager::DialogClosedCallback
           callback_on_button_clicked,
       base::OnceClosure callback_on_cancelled);
diff --git a/components/javascript_dialogs/app_modal_dialog_controller.cc b/components/javascript_dialogs/app_modal_dialog_controller.cc
index 821c4fd..75f27d7 100644
--- a/components/javascript_dialogs/app_modal_dialog_controller.cc
+++ b/components/javascript_dialogs/app_modal_dialog_controller.cc
@@ -27,15 +27,15 @@
 const int kDefaultPromptMaxRows = 24;
 const int kDefaultPromptMaxCols = 132;
 
-base::string16 EnforceMaxTextSize(const base::string16& in_string) {
-  base::string16 out_string;
+std::u16string EnforceMaxTextSize(const std::u16string& in_string) {
+  std::u16string out_string;
   gfx::ElideRectangleString(in_string, kMessageTextMaxRows, kMessageTextMaxCols,
                             false, &out_string);
   return out_string;
 }
 
-base::string16 EnforceMaxPromptSize(const base::string16& in_string) {
-  base::string16 out_string;
+std::u16string EnforceMaxPromptSize(const std::u16string& in_string) {
+  std::u16string out_string;
   gfx::ElideRectangleString(in_string, kDefaultPromptMaxRows,
                             kDefaultPromptMaxCols, false, &out_string);
   return out_string;
@@ -47,14 +47,14 @@
 const size_t kMessageTextMaxSize = 2000;
 const size_t kDefaultPromptMaxSize = 2000;
 
-base::string16 EnforceMaxTextSize(const base::string16& in_string) {
-  base::string16 out_string;
+std::u16string EnforceMaxTextSize(const std::u16string& in_string) {
+  std::u16string out_string;
   gfx::ElideString(in_string, kMessageTextMaxSize, &out_string);
   return out_string;
 }
 
-base::string16 EnforceMaxPromptSize(const base::string16& in_string) {
-  base::string16 out_string;
+std::u16string EnforceMaxPromptSize(const std::u16string& in_string) {
+  std::u16string out_string;
   gfx::ElideString(in_string, kDefaultPromptMaxSize, &out_string);
   return out_string;
 }
@@ -69,10 +69,10 @@
 AppModalDialogController::AppModalDialogController(
     content::WebContents* web_contents,
     ExtraDataMap* extra_data_map,
-    const base::string16& title,
+    const std::u16string& title,
     content::JavaScriptDialogType javascript_dialog_type,
-    const base::string16& message_text,
-    const base::string16& default_prompt_text,
+    const std::u16string& message_text,
+    const std::u16string& default_prompt_text,
     bool display_suppress_checkbox,
     bool is_before_unload_dialog,
     bool is_reload,
@@ -132,7 +132,7 @@
     return;
 
   valid_ = false;
-  CallDialogClosedCallback(false, base::string16());
+  CallDialogClosedCallback(false, std::u16string());
   if (view_)
     CloseModalDialog();
 }
@@ -146,12 +146,12 @@
   // is a temporary workaround.
   CompleteDialog();
 
-  NotifyDelegate(false, base::string16(), suppress_js_messages);
+  NotifyDelegate(false, std::u16string(), suppress_js_messages);
 }
 
-void AppModalDialogController::OnAccept(const base::string16& prompt_text,
+void AppModalDialogController::OnAccept(const std::u16string& prompt_text,
                                         bool suppress_js_messages) {
-  base::string16 prompt_text_to_use = prompt_text;
+  std::u16string prompt_text_to_use = prompt_text;
   // This is only for testing.
   if (use_override_prompt_text_)
     prompt_text_to_use = override_prompt_text_;
@@ -161,17 +161,17 @@
 }
 
 void AppModalDialogController::OnClose() {
-  NotifyDelegate(false, base::string16(), false);
+  NotifyDelegate(false, std::u16string(), false);
 }
 
 void AppModalDialogController::SetOverridePromptText(
-    const base::string16& override_prompt_text) {
+    const std::u16string& override_prompt_text) {
   override_prompt_text_ = override_prompt_text;
   use_override_prompt_text_ = true;
 }
 
 void AppModalDialogController::NotifyDelegate(bool success,
-                                              const base::string16& user_input,
+                                              const std::u16string& user_input,
                                               bool suppress_js_messages) {
   if (!valid_)
     return;
@@ -194,7 +194,7 @@
 
 void AppModalDialogController::CallDialogClosedCallback(
     bool success,
-    const base::string16& user_input) {
+    const std::u16string& user_input) {
   if (!callback_.is_null())
     std::move(callback_).Run(success, user_input);
 }
diff --git a/components/javascript_dialogs/app_modal_dialog_controller.h b/components/javascript_dialogs/app_modal_dialog_controller.h
index 0450d77..69463ed 100644
--- a/components/javascript_dialogs/app_modal_dialog_controller.h
+++ b/components/javascript_dialogs/app_modal_dialog_controller.h
@@ -37,10 +37,10 @@
   AppModalDialogController(
       content::WebContents* web_contents,
       ExtraDataMap* extra_data_map,
-      const base::string16& title,
+      const std::u16string& title,
       content::JavaScriptDialogType javascript_dialog_type,
-      const base::string16& message_text,
-      const base::string16& default_prompt_text,
+      const std::u16string& message_text,
+      const std::u16string& default_prompt_text,
       bool display_suppress_checkbox,
       bool is_before_unload_dialog,
       bool is_reload,
@@ -68,7 +68,7 @@
 
   // Callbacks from NativeDialog when the user accepts or cancels the dialog.
   void OnCancel(bool suppress_js_messages);
-  void OnAccept(const base::string16& prompt_text, bool suppress_js_messages);
+  void OnAccept(const std::u16string& prompt_text, bool suppress_js_messages);
 
   // NOTE: This is only called under Views, and should be removed. Any critical
   // work should be done in OnCancel or OnAccept. See crbug.com/63732 for more.
@@ -76,17 +76,17 @@
 
   // Used only for testing. The dialog will use the given text when notifying
   // its delegate instead of whatever the UI reports.
-  void SetOverridePromptText(const base::string16& prompt_text);
+  void SetOverridePromptText(const std::u16string& prompt_text);
 
   // Accessors.
-  base::string16 title() const { return title_; }
+  std::u16string title() const { return title_; }
   AppModalDialogView* view() const { return view_; }
   content::WebContents* web_contents() const { return web_contents_; }
   content::JavaScriptDialogType javascript_dialog_type() const {
     return javascript_dialog_type_;
   }
-  base::string16 message_text() const { return message_text_; }
-  base::string16 default_prompt_text() const { return default_prompt_text_; }
+  std::u16string message_text() const { return message_text_; }
+  std::u16string default_prompt_text() const { return default_prompt_text_; }
   bool display_suppress_checkbox() const { return display_suppress_checkbox_; }
   bool is_before_unload_dialog() const { return is_before_unload_dialog_; }
   bool is_reload() const { return is_reload_; }
@@ -94,18 +94,18 @@
  private:
   // Notifies the delegate with the result of the dialog.
   void NotifyDelegate(bool success,
-                      const base::string16& prompt_text,
+                      const std::u16string& prompt_text,
                       bool suppress_js_messages);
 
   void CallDialogClosedCallback(bool success,
-                                const base::string16& prompt_text);
+                                const std::u16string& prompt_text);
 
   // Completes dialog handling, shows next modal dialog from the queue.
   // TODO(beng): Get rid of this method.
   void CompleteDialog();
 
   // The title of the dialog.
-  const base::string16 title_;
+  const std::u16string title_;
 
   // False if the dialog should no longer be shown, e.g. because the underlying
   // tab navigated away while the dialog was queued.
@@ -124,8 +124,8 @@
 
   // Information about the message box is held in the following variables.
   const content::JavaScriptDialogType javascript_dialog_type_;
-  const base::string16 message_text_;
-  const base::string16 default_prompt_text_;
+  const std::u16string message_text_;
+  const std::u16string default_prompt_text_;
   const bool display_suppress_checkbox_;
   const bool is_before_unload_dialog_;
   const bool is_reload_;
@@ -134,7 +134,7 @@
 
   // Used only for testing. Specifies alternative prompt text that should be
   // used when notifying the delegate, if |use_override_prompt_text_| is true.
-  base::string16 override_prompt_text_;
+  std::u16string override_prompt_text_;
   bool use_override_prompt_text_;
 
   DISALLOW_COPY_AND_ASSIGN(AppModalDialogController);
diff --git a/components/javascript_dialogs/app_modal_dialog_manager.cc b/components/javascript_dialogs/app_modal_dialog_manager.cc
index 723b95bb..e3ef748 100644
--- a/components/javascript_dialogs/app_modal_dialog_manager.cc
+++ b/components/javascript_dialogs/app_modal_dialog_manager.cc
@@ -78,7 +78,7 @@
 
 AppModalDialogManager::~AppModalDialogManager() {}
 
-base::string16 AppModalDialogManager::GetTitle(
+std::u16string AppModalDialogManager::GetTitle(
     content::WebContents* web_contents,
     const GURL& alerting_frame_url) {
   // For extensions, show the extension name, but only if the origin of
@@ -117,7 +117,7 @@
 }  // namespace
 
 // static
-base::string16 AppModalDialogManager::GetTitleImpl(
+std::u16string AppModalDialogManager::GetTitleImpl(
     const GURL& parent_frame_url,
     const GURL& alerting_frame_url) {
   GURL unwrapped_parent_frame_url = UnwrapURL(parent_frame_url);
@@ -129,11 +129,11 @@
   if (unwrapped_alerting_frame_url.IsStandard() &&
       !unwrapped_alerting_frame_url.SchemeIsFile()) {
 #if defined(OS_ANDROID)
-    base::string16 url_string = url_formatter::FormatUrlForSecurityDisplay(
+    std::u16string url_string = url_formatter::FormatUrlForSecurityDisplay(
         unwrapped_alerting_frame_url,
         url_formatter::SchemeDisplay::OMIT_HTTP_AND_HTTPS);
 #else
-    base::string16 url_string = url_formatter::ElideHost(
+    std::u16string url_string = url_formatter::ElideHost(
         unwrapped_alerting_frame_url, gfx::FontList(), kUrlElideWidth);
 #endif
     return l10n_util::GetStringFUTF16(
@@ -151,8 +151,8 @@
     content::WebContents* web_contents,
     content::RenderFrameHost* render_frame_host,
     content::JavaScriptDialogType dialog_type,
-    const base::string16& message_text,
-    const base::string16& default_prompt_text,
+    const std::u16string& message_text,
+    const std::u16string& default_prompt_text,
     DialogClosedCallback callback,
     bool* did_suppress_message) {
   *did_suppress_message = false;
@@ -165,7 +165,7 @@
     return;
   }
 
-  base::string16 dialog_title =
+  std::u16string dialog_title =
       GetTitle(web_contents, render_frame_host->GetLastCommittedURL());
 
   extensions_client_->OnDialogOpened(web_contents);
@@ -202,7 +202,7 @@
   if (extra_data->suppress_javascript_messages_) {
     // If a site harassed the user enough for them to put it on mute, then it
     // lost its privilege to deny unloading.
-    std::move(callback).Run(true, base::string16());
+    std::move(callback).Run(true, std::u16string());
     return;
   }
 
@@ -218,7 +218,7 @@
   // This message used to be customizable, but it was frequently abused by
   // scam websites so the specification was changed.
 
-  base::string16 title;
+  std::u16string title;
   if (is_app) {
     title = l10n_util::GetStringUTF16(
         is_reload ? IDS_BEFORERELOAD_APP_MESSAGEBOX_TITLE
@@ -228,7 +228,7 @@
                                           ? IDS_BEFORERELOAD_MESSAGEBOX_TITLE
                                           : IDS_BEFOREUNLOAD_MESSAGEBOX_TITLE);
   }
-  const base::string16 message =
+  const std::u16string message =
       l10n_util::GetStringUTF16(IDS_BEFOREUNLOAD_MESSAGEBOX_MESSAGE);
 
   extensions_client_->OnDialogOpened(web_contents);
@@ -236,7 +236,7 @@
   AppModalDialogQueue::GetInstance()->AddDialog(new AppModalDialogController(
       web_contents, &javascript_dialog_extra_data_, title,
       content::JAVASCRIPT_DIALOG_TYPE_CONFIRM, message,
-      base::string16(),  // default_prompt_text
+      std::u16string(),  // default_prompt_text
       ShouldDisplaySuppressCheckbox(extra_data),
       true,  // is_before_unload_dialog
       is_reload,
@@ -248,7 +248,7 @@
 bool AppModalDialogManager::HandleJavaScriptDialog(
     content::WebContents* web_contents,
     bool accept,
-    const base::string16* prompt_override) {
+    const std::u16string* prompt_override) {
   AppModalDialogQueue* dialog_queue = AppModalDialogQueue::GetInstance();
   if (!dialog_queue->HasActiveDialog() ||
       dialog_queue->active_dialog()->web_contents() != web_contents) {
@@ -293,7 +293,7 @@
 void AppModalDialogManager::OnDialogClosed(content::WebContents* web_contents,
                                            DialogClosedCallback callback,
                                            bool success,
-                                           const base::string16& user_input) {
+                                           const std::u16string& user_input) {
   // If an extension opened this dialog then the extension may shut down its
   // lazy background page after the dialog closes. (Dialogs are closed before
   // their WebContents is destroyed so |web_contents| is still valid here.)
diff --git a/components/javascript_dialogs/app_modal_dialog_manager.h b/components/javascript_dialogs/app_modal_dialog_manager.h
index b21870d..1fcff0a 100644
--- a/components/javascript_dialogs/app_modal_dialog_manager.h
+++ b/components/javascript_dialogs/app_modal_dialog_manager.h
@@ -40,7 +40,7 @@
   void SetExtensionsClient(std::unique_ptr<ExtensionsClient> extensions_client);
 
   // Gets the title for a dialog.
-  base::string16 GetTitle(content::WebContents* web_contents,
+  std::u16string GetTitle(content::WebContents* web_contents,
                           const GURL& alerting_frame_url);
 
   // Displays a dialog asking the user if they want to leave a page. Displays
@@ -56,8 +56,8 @@
   void RunJavaScriptDialog(content::WebContents* web_contents,
                            content::RenderFrameHost* render_frame_host,
                            content::JavaScriptDialogType dialog_type,
-                           const base::string16& message_text,
-                           const base::string16& default_prompt_text,
+                           const std::u16string& message_text,
+                           const std::u16string& default_prompt_text,
                            DialogClosedCallback callback,
                            bool* did_suppress_message) override;
   void RunBeforeUnloadDialog(content::WebContents* web_contents,
@@ -66,7 +66,7 @@
                              DialogClosedCallback callback) override;
   bool HandleJavaScriptDialog(content::WebContents* web_contents,
                               bool accept,
-                              const base::string16* prompt_override) override;
+                              const std::u16string* prompt_override) override;
   void CancelDialogs(content::WebContents* web_contents,
                      bool reset_state) override;
 
@@ -82,9 +82,9 @@
   void OnDialogClosed(content::WebContents* web_contents,
                       DialogClosedCallback callback,
                       bool success,
-                      const base::string16& user_input);
+                      const std::u16string& user_input);
 
-  static base::string16 GetTitleImpl(const GURL& parent_frame_url,
+  static std::u16string GetTitleImpl(const GURL& parent_frame_url,
                                      const GURL& alerting_frame_url);
 
   // Mapping between the WebContents and their extra data. The key
diff --git a/components/javascript_dialogs/app_modal_dialog_manager_unittest.cc b/components/javascript_dialogs/app_modal_dialog_manager_unittest.cc
index 55ee1a01..6e4d2cd 100644
--- a/components/javascript_dialogs/app_modal_dialog_manager_unittest.cc
+++ b/components/javascript_dialogs/app_modal_dialog_manager_unittest.cc
@@ -86,7 +86,7 @@
   };
 
   for (const auto& test_case : cases) {
-    base::string16 result = AppModalDialogManager::GetTitleImpl(
+    std::u16string result = AppModalDialogManager::GetTitleImpl(
         GURL(test_case.parent_url), GURL(test_case.alerting_url));
 #if defined(OS_ANDROID)
     EXPECT_EQ(test_case.expected_android, base::UTF16ToUTF8(result));
diff --git a/components/javascript_dialogs/tab_modal_dialog_manager.cc b/components/javascript_dialogs/tab_modal_dialog_manager.cc
index e4f89656..6890e2a 100644
--- a/components/javascript_dialogs/tab_modal_dialog_manager.cc
+++ b/components/javascript_dialogs/tab_modal_dialog_manager.cc
@@ -112,7 +112,7 @@
 }  // namespace
 
 TabModalDialogManager::~TabModalDialogManager() {
-  CloseDialog(DismissalCause::kTabHelperDestroyed, false, base::string16());
+  CloseDialog(DismissalCause::kTabHelperDestroyed, false, std::u16string());
 }
 
 void TabModalDialogManager::BrowserActiveStateChanged() {
@@ -123,7 +123,7 @@
 }
 
 void TabModalDialogManager::CloseDialogWithReason(DismissalCause reason) {
-  CloseDialog(reason, false, base::string16());
+  CloseDialog(reason, false, std::u16string());
 }
 
 void TabModalDialogManager::SetDialogShownCallbackForTesting(
@@ -137,7 +137,7 @@
 
 void TabModalDialogManager::ClickDialogButtonForTesting(
     bool accept,
-    const base::string16& user_input) {
+    const std::u16string& user_input) {
   DCHECK(!!dialog_);
   CloseDialog(DismissalCause::kDialogButtonClicked, accept, user_input);
 }
@@ -151,8 +151,8 @@
     content::WebContents* alerting_web_contents,
     content::RenderFrameHost* render_frame_host,
     content::JavaScriptDialogType dialog_type,
-    const base::string16& message_text,
-    const base::string16& default_prompt_text,
+    const std::u16string& message_text,
+    const std::u16string& default_prompt_text,
     DialogClosedCallback callback,
     bool* did_suppress_message) {
   DCHECK_EQ(alerting_web_contents,
@@ -190,7 +190,7 @@
   }
 
   // Close any dialog already showing.
-  CloseDialog(DismissalCause::kSubsequentDialogShown, false, base::string16());
+  CloseDialog(DismissalCause::kSubsequentDialogShown, false, std::u16string());
 
   bool make_pending = false;
   if (!delegate_->IsWebContentsForemost() &&
@@ -205,7 +205,7 @@
       case content::JAVASCRIPT_DIALOG_TYPE_ALERT: {
         // When an alert fires in the background, make the callback so that the
         // render process can continue.
-        std::move(callback).Run(true, base::string16());
+        std::move(callback).Run(true, std::u16string());
         callback.Reset();
 
         delegate_->SetTabNeedsAttention(true);
@@ -239,15 +239,15 @@
   const int kMessageTextMaxRows = 24;
   const int kMessageTextMaxCols = 80;
   const size_t kDefaultPromptMaxSize = 2000;
-  base::string16 truncated_message_text;
+  std::u16string truncated_message_text;
   gfx::ElideRectangleString(message_text, kMessageTextMaxRows,
                             kMessageTextMaxCols, false,
                             &truncated_message_text);
-  base::string16 truncated_default_prompt_text;
+  std::u16string truncated_default_prompt_text;
   gfx::ElideString(default_prompt_text, kDefaultPromptMaxSize,
                    &truncated_default_prompt_text);
 
-  base::string16 title = GetAppModalDialogManager()->GetTitle(
+  std::u16string title = GetAppModalDialogManager()->GetTitle(
       alerting_web_contents, alerting_frame_url);
   dialog_callback_ = std::move(callback);
   dialog_type_ = dialog_type;
@@ -262,7 +262,7 @@
                        DismissalCause::kDialogButtonClicked),
         base::BindOnce(&TabModalDialogManager::CloseDialog,
                        base::Unretained(this), DismissalCause::kDialogClosed,
-                       false, base::string16()));
+                       false, std::u16string()));
   } else {
     DCHECK(!pending_dialog_);
     dialog_ = delegate_->CreateNewDialog(
@@ -273,7 +273,7 @@
                        DismissalCause::kDialogButtonClicked),
         base::BindOnce(&TabModalDialogManager::CloseDialog,
                        base::Unretained(this), DismissalCause::kDialogClosed,
-                       false, base::string16()));
+                       false, std::u16string()));
   }
 
   delegate_->WillRunDialog();
@@ -320,7 +320,7 @@
 bool TabModalDialogManager::HandleJavaScriptDialog(
     content::WebContents* web_contents,
     bool accept,
-    const base::string16* prompt_override) {
+    const std::u16string* prompt_override) {
   if (dialog_ || pending_dialog_) {
     CloseDialog(DismissalCause::kHandleDialogCalled, accept,
                 prompt_override ? *prompt_override : dialog_->GetUserInput());
@@ -334,7 +334,7 @@
 
 void TabModalDialogManager::CancelDialogs(content::WebContents* web_contents,
                                           bool reset_state) {
-  CloseDialog(DismissalCause::kCancelDialogsCalled, false, base::string16());
+  CloseDialog(DismissalCause::kCancelDialogsCalled, false, std::u16string());
 
   // Cancel any app-modal dialogs being run by the app-modal dialog system.
   return GetAppModalDialogManager()->CancelDialogs(web_contents, reset_state);
@@ -355,7 +355,7 @@
     content::NavigationHandle* navigation_handle) {
   // Close the dialog if the user started a new navigation. This allows reloads
   // and history navigations to proceed.
-  CloseDialog(DismissalCause::kTabNavigated, false, base::string16());
+  CloseDialog(DismissalCause::kTabNavigated, false, std::u16string());
 }
 
 TabModalDialogManager::TabModalDialogManager(
@@ -393,17 +393,17 @@
     // When the user switches tabs, make the callback so that the render process
     // can continue.
     if (dialog_callback_) {
-      std::move(dialog_callback_).Run(true, base::string16());
+      std::move(dialog_callback_).Run(true, std::u16string());
       dialog_callback_.Reset();
     }
   } else {
-    CloseDialog(cause, false, base::string16());
+    CloseDialog(cause, false, std::u16string());
   }
 }
 
 void TabModalDialogManager::CloseDialog(DismissalCause cause,
                                         bool success,
-                                        const base::string16& user_input) {
+                                        const std::u16string& user_input) {
   if (!dialog_ && !pending_dialog_)
     return;
 
diff --git a/components/javascript_dialogs/tab_modal_dialog_manager.h b/components/javascript_dialogs/tab_modal_dialog_manager.h
index d91bf569..549dc57 100644
--- a/components/javascript_dialogs/tab_modal_dialog_manager.h
+++ b/components/javascript_dialogs/tab_modal_dialog_manager.h
@@ -99,7 +99,7 @@
   void SetDialogShownCallbackForTesting(base::OnceClosure callback);
   bool IsShowingDialogForTesting() const;
   void ClickDialogButtonForTesting(bool accept,
-                                   const base::string16& user_input);
+                                   const std::u16string& user_input);
   using DialogDismissedCallback = base::OnceCallback<void(DismissalCause)>;
   void SetDialogDismissedCallbackForTesting(DialogDismissedCallback callback);
 
@@ -107,8 +107,8 @@
   void RunJavaScriptDialog(content::WebContents* web_contents,
                            content::RenderFrameHost* render_frame_host,
                            content::JavaScriptDialogType dialog_type,
-                           const base::string16& message_text,
-                           const base::string16& default_prompt_text,
+                           const std::u16string& message_text,
+                           const std::u16string& default_prompt_text,
                            DialogClosedCallback callback,
                            bool* did_suppress_message) override;
   void RunBeforeUnloadDialog(content::WebContents* web_contents,
@@ -117,7 +117,7 @@
                              DialogClosedCallback callback) override;
   bool HandleJavaScriptDialog(content::WebContents* web_contents,
                               bool accept,
-                              const base::string16* prompt_override) override;
+                              const std::u16string* prompt_override) override;
   void CancelDialogs(content::WebContents* web_contents,
                      bool reset_state) override;
 
@@ -143,7 +143,7 @@
   // open dialog.
   void CloseDialog(DismissalCause cause,
                    bool success,
-                   const base::string16& user_input);
+                   const std::u16string& user_input);
 
   // There can be at most one dialog (pending or not) being shown at any given
   // time on a tab. Depending on the type of the dialog, the variables
diff --git a/components/javascript_dialogs/tab_modal_dialog_manager_delegate.h b/components/javascript_dialogs/tab_modal_dialog_manager_delegate.h
index 4f718b7..396e6f43 100644
--- a/components/javascript_dialogs/tab_modal_dialog_manager_delegate.h
+++ b/components/javascript_dialogs/tab_modal_dialog_manager_delegate.h
@@ -25,10 +25,10 @@
   // Factory function for creating a tab modal view.
   virtual base::WeakPtr<TabModalDialogView> CreateNewDialog(
       content::WebContents* alerting_web_contents,
-      const base::string16& title,
+      const std::u16string& title,
       content::JavaScriptDialogType dialog_type,
-      const base::string16& message_text,
-      const base::string16& default_prompt_text,
+      const std::u16string& message_text,
+      const std::u16string& default_prompt_text,
       content::JavaScriptDialogManager::DialogClosedCallback dialog_callback,
       base::OnceClosure dialog_closed_callback) = 0;
 
diff --git a/components/javascript_dialogs/tab_modal_dialog_view.h b/components/javascript_dialogs/tab_modal_dialog_view.h
index e68401c..6da0e901 100644
--- a/components/javascript_dialogs/tab_modal_dialog_view.h
+++ b/components/javascript_dialogs/tab_modal_dialog_view.h
@@ -22,7 +22,7 @@
   virtual void CloseDialogWithoutCallback() = 0;
 
   // Returns the current value of the user input for a prompt dialog.
-  virtual base::string16 GetUserInput() = 0;
+  virtual std::u16string GetUserInput() = 0;
 };
 
 }  // namespace javascript_dialogs
diff --git a/components/javascript_dialogs/views/app_modal_dialog_view_views.cc b/components/javascript_dialogs/views/app_modal_dialog_view_views.cc
index fb043e84..bdd5c25 100644
--- a/components/javascript_dialogs/views/app_modal_dialog_view_views.cc
+++ b/components/javascript_dialogs/views/app_modal_dialog_view_views.cc
@@ -103,7 +103,7 @@
 //////////////////////////////////////////////////////////////////////////////
 // AppModalDialogViewViews, views::DialogDelegate implementation:
 
-base::string16 AppModalDialogViewViews::GetWindowTitle() const {
+std::u16string AppModalDialogViewViews::GetWindowTitle() const {
   return controller_->title();
 }
 
diff --git a/components/javascript_dialogs/views/app_modal_dialog_view_views.h b/components/javascript_dialogs/views/app_modal_dialog_view_views.h
index 758ec2b..856be25 100644
--- a/components/javascript_dialogs/views/app_modal_dialog_view_views.h
+++ b/components/javascript_dialogs/views/app_modal_dialog_view_views.h
@@ -34,7 +34,7 @@
   bool IsShowing() const override;
 
   // views::DialogDelegate:
-  base::string16 GetWindowTitle() const override;
+  std::u16string GetWindowTitle() const override;
   ui::ModalType GetModalType() const override;
   views::View* GetContentsView() override;
   views::View* GetInitiallyFocusedView() override;