Switch Extensions::TabHelper to use WebContents, WebContentsUserData.

chrome/browser/ui/ash/launcher/browser_launcher_item_controller.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/ui/ash/launcher/browser_launcher_item_controller.h"
 
 #include "ash/launcher/launcher.h"
 #include "ash/launcher/launcher_model.h"
 #include "ash/shell.h"
 #include "ash/wm/window_util.h"
@@ skipping 233 matching lines @@
     return;
 
   ash::LauncherItem item = launcher_model()->items()[item_index];
   if (type() == TYPE_EXTENSION_PANEL) {
     if (!favicon_loader_.get() ||
         favicon_loader_->web_contents() != tab->web_contents()) {
       favicon_loader_.reset(
           new LauncherFaviconLoader(this, tab->web_contents()));
     }
     // Update the icon for extension panels.
+    extensions::TabHelper* extensions_tab_helper =
+        extensions::TabHelper::FromWebContents(tab->web_contents());
     SkBitmap new_image = favicon_loader_->GetFavicon();
-    if (new_image.isNull() &&
-        tab->extension_tab_helper()->GetExtensionAppIcon()) {
-      new_image = *tab->extension_tab_helper()->GetExtensionAppIcon();
-    }
+    if (new_image.isNull() && extensions_tab_helper->GetExtensionAppIcon())
+      new_image = *extensions_tab_helper->GetExtensionAppIcon();
     // Only update the icon if we have a new image, or none has been set yet.
     // This avoids flickering to an empty image when a pinned app is opened.
     if (!new_image.isNull())
       item.image = new_image;
     else if (item.image.isNull())
       item.image = extensions::Extension::GetDefaultIcon(true);
   } else {
     DCHECK_EQ(TYPE_TABBED, type());
     ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
     if (tab->favicon_tab_helper()->ShouldDisplayFavicon()) {
@@ skipping 20 matching lines @@
       app_state = ChromeLauncherController::APP_STATE_ACTIVE;
   } else {
     app_state = ChromeLauncherController::APP_STATE_INACTIVE;
   }
   launcher_controller()->UpdateAppState(tab, app_state);
 }
 
 ash::LauncherModel* BrowserLauncherItemController::launcher_model() {
   return launcher_controller()->model();
 }