[WebLayer] Add browsertest for SecurityStateClient code.

Add a browsertest to verify expected SecurityStateClient behavior.

Bug: 1052375
Change-Id: I6a063ce298e6576513b019a688452458fd76650e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2144032
Reviewed-by: Colin Blundell <[email protected]>
Commit-Queue: Mugdha Lakhani <[email protected]>
Cr-Commit-Position: refs/heads/master@{#757847}
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 1973f26..c43b8568 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -1195,6 +1195,8 @@
   CreateNetworkQualityObserver();
 
 #if defined(OS_ANDROID)
+  // This needs to be here so that SecurityStateClient is non-null when
+  // SecurityStateModel code is called.
   security_state::SetSecurityStateClient(new ChromeSecurityStateClient());
 #endif
 }