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

chrome/renderer/chrome_render_thread_observer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/renderer/chrome_render_thread_observer.h"
 
 #include <stddef.h>
 
 #include <limits>
 #include <memory>
@@ skipping 218 matching lines @@
     base::WeakPtr<ChromeRenderThreadObserver> observer,
     mojo::InterfaceRequest<mojom::ResourceUsageReporter> request) {
   new ResourceUsageReporterImpl(observer, std::move(request));
 }
 
 }  // namespace
 
 bool ChromeRenderThreadObserver::is_incognito_process_ = false;
 
 ChromeRenderThreadObserver::ChromeRenderThreadObserver()
-    : field_trial_syncer_(content::RenderThread::Get()), weak_factory_(this) {
+    : field_trial_syncer_(this), weak_factory_(this) {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
 
   RenderThread* thread = RenderThread::Get();
   resource_delegate_.reset(new RendererResourceDelegate());
   thread->SetResourceDispatcherDelegate(resource_delegate_.get());
 
   thread->GetServiceRegistry()->AddService(
       base::Bind(CreateResourceUsageReporter, weak_factory_.GetWeakPtr()));
 
@@ skipping 27 matching lines @@
     IPC_MESSAGE_HANDLER(ChromeViewMsg_SetIsIncognitoProcess,
                         OnSetIsIncognitoProcess)
     IPC_MESSAGE_HANDLER(ChromeViewMsg_SetFieldTrialGroup, OnSetFieldTrialGroup)
     IPC_MESSAGE_HANDLER(ChromeViewMsg_SetContentSettingRules,
                         OnSetContentSettingRules)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
+void ChromeRenderThreadObserver::OnFieldTrialGroupFinalized(
+    const std::string& trial_name,
+    const std::string& group_name) {
+  content::RenderThread::Get()->Send(
+      new ChromeViewHostMsg_FieldTrialActivated(trial_name));
+}
+
 void ChromeRenderThreadObserver::OnSetIsIncognitoProcess(
     bool is_incognito_process) {
   is_incognito_process_ = is_incognito_process;
 }
 
 void ChromeRenderThreadObserver::OnSetContentSettingRules(
     const RendererContentSettingRules& rules) {
   content_setting_rules_ = rules;
 }
 
 void ChromeRenderThreadObserver::OnSetFieldTrialGroup(
     const std::string& trial_name,
     const std::string& group_name) {
   field_trial_syncer_.OnSetFieldTrialGroup(trial_name, group_name);
 }
 
 const RendererContentSettingRules*
 ChromeRenderThreadObserver::content_setting_rules() const {
   return &content_setting_rules_;
 }