Create MediaRouterActionController and MediaRouterUIService

chrome/browser/extensions/component_migration_helper.h

Index: chrome/browser/extensions/component_migration_helper.h
diff --git a/chrome/browser/extensions/component_migration_helper.h b/chrome/browser/extensions/component_migration_helper.h
index 66f938ed4a1a7f2603d056981158b9995abea3a8..5938597ffce16f0f4cca3f65935a00132af69c5f 100644
--- a/chrome/browser/extensions/component_migration_helper.h
+++ b/chrome/browser/extensions/component_migration_helper.h
@@ -107,11 +107,13 @@ class ComponentMigrationHelper : public ExtensionRegistryObserver {
   void OnExtensionReady(content::BrowserContext* browser_context,
                         const Extension* extension) override;
 
- protected:
-  // Protected for unit testing.
+  // Gets and sets the preference for whether to put the component action with
+  // the given ID on the toolbar (or in the overflow menu).
+  bool GetComponentActionPref(const std::string& component_action_id) const;
   void SetComponentActionPref(const std::string& component_action_id,

[imcheng, 2016/09/13 23:13:09]

Why is SetComponentActionPref public? I don't see any new callsites introduced
in this patch?

[takumif, 2016/09/14 04:00:51]

It's for MRAction to call, which is in the other patch.

                               bool enabled);
 
+ protected:
   // A set of component action ids whose features are currently enabled.
   // Protected for unit testing.
   std::set<std::string> enabled_actions_;