Make field trials activated in the GPU process be reflected in browser.

chrome/renderer/chrome_render_thread_observer.h

Index: chrome/renderer/chrome_render_thread_observer.h
diff --git a/chrome/renderer/chrome_render_thread_observer.h b/chrome/renderer/chrome_render_thread_observer.h
index ed571ae98d8222d1430c8d70a2f2f5fe60e04525..0213e51ad14a20b6526403032308aff06a0ea878 100644
--- a/chrome/renderer/chrome_render_thread_observer.h
+++ b/chrome/renderer/chrome_render_thread_observer.h
@@ -30,7 +30,8 @@ class ResourceDispatcherDelegate;
 // a RenderView) for Chrome specific messages that the content layer doesn't
 // happen.  If a few messages are related, they should probably have their own
 // observer.
-class ChromeRenderThreadObserver : public content::RenderThreadObserver {
+class ChromeRenderThreadObserver : public content::RenderThreadObserver,
+                                   public base::FieldTrialList::Observer {
  public:
   ChromeRenderThreadObserver();
   ~ChromeRenderThreadObserver() override;
@@ -49,6 +50,10 @@ class ChromeRenderThreadObserver : public content::RenderThreadObserver {
   // content::RenderThreadObserver:
   bool OnControlMessageReceived(const IPC::Message& message) override;
 
+  // base::FieldTrialList::Observer:
+  void OnFieldTrialGroupFinalized(const std::string& trial_name,
+                                  const std::string& group_name) override;
+
   void OnSetIsIncognitoProcess(bool is_incognito_process);
   void OnSetContentSettingsForCurrentURL(
       const GURL& url, const ContentSettings& content_settings);