Exclude Background Mode code from ChromeOS

Split "enable_background" to "enable_background_mode" and
"enable_background_contents" (latter one is used in chrome).

Bug: 527045
Change-Id: Ia8d96379b74ecc5fb54fe0e6688a79e0ef9fa767
Reviewed-on: https://chromium-review.googlesource.com/822475
Reviewed-by: Drew Wilson <[email protected]>
Reviewed-by: Jochen Eisinger <[email protected]>
Commit-Queue: Denis Kuznetsov <[email protected]>
Cr-Commit-Position: refs/heads/master@{#524374}
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 570e4c1..575f8d0 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -152,7 +152,7 @@
 #include "components/keep_alive_registry/keep_alive_registry.h"
 #endif
 
-#if BUILDFLAG(ENABLE_BACKGROUND)
+#if BUILDFLAG(ENABLE_BACKGROUND_MODE)
 #include "chrome/browser/background/background_mode_manager.h"
 #endif
 
@@ -897,7 +897,7 @@
 
 BackgroundModeManager* BrowserProcessImpl::background_mode_manager() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-#if BUILDFLAG(ENABLE_BACKGROUND)
+#if BUILDFLAG(ENABLE_BACKGROUND_MODE)
   if (!background_mode_manager_)
     CreateBackgroundModeManager();
   return background_mode_manager_.get();
@@ -909,7 +909,7 @@
 
 void BrowserProcessImpl::set_background_mode_manager_for_test(
     std::unique_ptr<BackgroundModeManager> manager) {
-#if BUILDFLAG(ENABLE_BACKGROUND)
+#if BUILDFLAG(ENABLE_BACKGROUND_MODE)
   background_mode_manager_ = std::move(manager);
 #endif
 }
@@ -1196,7 +1196,7 @@
 }
 
 void BrowserProcessImpl::CreateBackgroundModeManager() {
-#if BUILDFLAG(ENABLE_BACKGROUND)
+#if BUILDFLAG(ENABLE_BACKGROUND_MODE)
   DCHECK(!background_mode_manager_);
   background_mode_manager_ = base::MakeUnique<BackgroundModeManager>(
       *base::CommandLine::ForCurrentProcess(),