Only return the visible page actions from PageActionController.

chrome/browser/extensions/extension_tab_helper.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/browser/extensions/extension_tab_helper.h"
 
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/webstore_inline_installer.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/restore_tab_helper.h"
@@ skipping 34 matching lines @@
 
 ExtensionTabHelper::~ExtensionTabHelper() {
 }
 
 void ExtensionTabHelper::CopyStateFrom(const ExtensionTabHelper& source) {
   SetExtensionApp(source.extension_app());
   extension_app_icon_ = source.extension_app_icon_;
 }
 
 void ExtensionTabHelper::PageActionStateChanged() {
+  // TODO(kalman): replace this with just the Observer interface.
   web_contents()->NotifyNavigationStateChanged(
       content::INVALIDATE_TYPE_PAGE_ACTIONS);
+
+  FOR_EACH_OBSERVER(Observer, observers_, OnPageActionStateChanged());
 }
 
 void ExtensionTabHelper::GetApplicationInfo(int32 page_id) {
   Send(new ExtensionMsg_GetApplicationInfo(routing_id(), page_id));
 }
 
+void ExtensionTabHelper::AddObserver(ExtensionTabHelper::Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void ExtensionTabHelper::RemoveObserver(
+    ExtensionTabHelper::Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
 void ExtensionTabHelper::SetExtensionApp(const Extension* extension) {
   DCHECK(!extension || extension->GetFullLaunchURL().is_valid());
   extension_app_ = extension;
 
   UpdateExtensionAppIcon(extension_app_);
 
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED,
       content::Source<ExtensionTabHelper>(this),
       content::NotificationService::NoDetails());
@@ skipping 268 matching lines @@
 void ExtensionTabHelper::OnInlineInstallFailure(int install_id,
                                                 int return_route_id,
                                                 const std::string& error) {
   Send(new ExtensionMsg_InlineWebstoreInstallResponse(
       return_route_id, install_id, false, error));
 }
 
 WebContents* ExtensionTabHelper::GetAssociatedWebContents() const {
   return web_contents();
 }