[Media Router] Unload the legacy Cast extension at install

chrome/browser/ui/toolbar/component_toolbar_actions_factory.h

Index: chrome/browser/ui/toolbar/component_toolbar_actions_factory.h
diff --git a/chrome/browser/ui/toolbar/component_toolbar_actions_factory.h b/chrome/browser/ui/toolbar/component_toolbar_actions_factory.h
index b9024817a6f7253f560222c25e4a12a020e1bc85..5805dc87e3b04bcb200162ea57b75905e21bde18 100644
--- a/chrome/browser/ui/toolbar/component_toolbar_actions_factory.h
+++ b/chrome/browser/ui/toolbar/component_toolbar_actions_factory.h
@@ -10,21 +10,24 @@
 #include <string>
 
 #include "base/macros.h"
+#include "base/scoped_observer.h"
+#include "extensions/browser/extension_registry_observer.h"
 
 class Browser;
-class ExtensionService;
 class Profile;
 class ToolbarActionsBar;
 class ToolbarActionViewController;
 
 namespace extensions {
 class ExtensionRegistry;
-}
+class ExtensionSystem;
+}  // namespace extensions
 
 // The registry for all component toolbar actions. Component toolbar actions
 // are actions that live in the toolbar (like extension actions), but are for
 // components of Chrome, such as Media Router.
-class ComponentToolbarActionsFactory {
+class ComponentToolbarActionsFactory
+    : public extensions::ExtensionRegistryObserver {
  public:
   // Extension and component action IDs.
   static const char kCastBetaExtensionId[];
@@ -32,7 +35,7 @@ class ComponentToolbarActionsFactory {
   static const char kMediaRouterActionId[];
 
   explicit ComponentToolbarActionsFactory(Profile* profile);
-  virtual ~ComponentToolbarActionsFactory();
+  ~ComponentToolbarActionsFactory() override;
 
   // Returns a set of IDs of the component actions that should be present when
   // the toolbar model is initialized.
@@ -53,21 +56,31 @@ class ComponentToolbarActionsFactory {
 
   // Unloads extensions that were migrated to component actions and therefore
   // are no longer needed.
-  void UnloadMigratedExtensions(ExtensionService* service,
-                                extensions::ExtensionRegistry* registry);
+  void UnloadMigratedExtensions();
+
+  // extensions::ExtensionRegistryObserver:
+  void OnExtensionInstalled(content::BrowserContext* browser_context,
+                            const extensions::Extension* extension,
+                            bool is_update) override;
 
  private:
-  // Unloads an extension if it is active.
-  void UnloadExtension(ExtensionService* service,
-                       extensions::ExtensionRegistry* registry,
-                       const std::string& extension_id);
+  // Unloads an extension if it is installed.
+  void UnloadExtension(const std::string& extension_id);
 
-  Profile* profile_;
+  Profile* const profile_;
 
   // IDs of component actions that should be added to the toolbar model when it
   // gets initialized.
   std::set<std::string> initial_ids_;
 
+  // The ExtensionRegistry and ExtensionSystem for the profile, used for
+  // detecting and unloading migrated extensions.
+  extensions::ExtensionRegistry* const extension_registry_;
+  extensions::ExtensionSystem* const extension_system_;
+
+  ScopedObserver<extensions::ExtensionRegistry, ExtensionRegistryObserver>
+      extension_registry_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(ComponentToolbarActionsFactory);
 };