[Media Router] Adds a contextual menu item to remove the MR component action.

chrome/browser/extensions/component_migration_helper.h

 // Copyright 2016 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_COMPONENT_MIGRATION_HELPER_H_
 #define CHROME_BROWSER_EXTENSIONS_COMPONENT_MIGRATION_HELPER_H_
 
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 82 matching lines @@
 
   // Call when we should potentially add the component action and unload
   // the extension.  PREREQUISITE: The extension action redesign MUST be
   // enabled.
   void OnFeatureEnabled(const std::string& component_action_id);
 
   // Call when we should potentially remove the component action and re-enable
   // extension loading.
   void OnFeatureDisabled(const std::string& component_action_id);
 
+  // Call when the user manually removes the component action from the toolbar.
+  void OnActionRemoved(const std::string& component_action_id);
+
   // extensions::ExtensionRegistryObserver:
   void OnExtensionReady(content::BrowserContext* browser_context,
                         const Extension* extension) override;
 
  protected:
   // Protected for unit testing.
   void SetComponentActionPref(const std::string& component_action_id,
                               bool enabled);
 
   // A set of component action ids whose features are currently enabled.
@@ skipping 21 matching lines @@
 
   // A list of pairs of component action ids and extension ids.
   std::vector<std::pair<std::string, ExtensionId>> migrated_actions_;
 
   DISALLOW_COPY_AND_ASSIGN(ComponentMigrationHelper);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_COMPONENT_MIGRATION_HELPER_H_