Convert ChromeViewMsg_SetFieldTrialGroup to use mojo.

chrome/renderer/chrome_render_thread_observer.cc

Index: chrome/renderer/chrome_render_thread_observer.cc
diff --git a/chrome/renderer/chrome_render_thread_observer.cc b/chrome/renderer/chrome_render_thread_observer.cc
index 996518506ab0188bad786eda5dea084785c04030..05c29158c9a9c08186583f65a0e95696e437fa87 100644
--- a/chrome/renderer/chrome_render_thread_observer.cc
+++ b/chrome/renderer/chrome_render_thread_observer.cc
@@ -30,7 +30,6 @@
 #include "build/build_config.h"
 #include "chrome/common/child_process_logging.h"
 #include "chrome/common/chrome_paths.h"
-#include "chrome/common/field_trial_recorder.mojom.h"
 #include "chrome/common/media/media_resource_provider.h"
 #include "chrome/common/net/net_resource_provider.h"
 #include "chrome/common/render_messages.h"
@@ -288,16 +287,6 @@ void ChromeRenderThreadObserver::UnregisterMojoInterfaces(
       chrome::mojom::RendererConfiguration::Name_);
 }
 
-bool ChromeRenderThreadObserver::OnControlMessageReceived(
-    const IPC::Message& message) {
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(ChromeRenderThreadObserver, message)
-    IPC_MESSAGE_HANDLER(ChromeViewMsg_SetFieldTrialGroup, OnSetFieldTrialGroup)
-    IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
-}
-
 void ChromeRenderThreadObserver::OnRenderProcessShutdown() {
   visited_link_slave_.reset();
 
@@ -324,17 +313,17 @@ void ChromeRenderThreadObserver::SetContentSettingRules(
   content_setting_rules_ = rules;
 }
 
-void ChromeRenderThreadObserver::OnRendererConfigurationAssociatedRequest(
-    chrome::mojom::RendererConfigurationAssociatedRequest request) {
-  renderer_configuration_bindings_.AddBinding(this, std::move(request));
-}
-
-void ChromeRenderThreadObserver::OnSetFieldTrialGroup(
+void ChromeRenderThreadObserver::SetFieldTrialGroup(
     const std::string& trial_name,
     const std::string& group_name) {
   field_trial_syncer_.OnSetFieldTrialGroup(trial_name, group_name);
 }
 
+void ChromeRenderThreadObserver::OnRendererConfigurationAssociatedRequest(
+    chrome::mojom::RendererConfigurationAssociatedRequest request) {
+  renderer_configuration_bindings_.AddBinding(this, std::move(request));
+}
+
 const RendererContentSettingRules*
 ChromeRenderThreadObserver::content_setting_rules() const {
   return &content_setting_rules_;