Remove usage of FOR_EACH_OBSERVER macro in ash/common

ash/common/wallpaper/wallpaper_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 "ash/common/wallpaper/wallpaper_controller.h"
 
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/wallpaper/wallpaper_controller_observer.h"
 #include "ash/common/wallpaper/wallpaper_delegate.h"
 #include "ash/common/wallpaper/wallpaper_view.h"
@@ skipping 61 matching lines @@
 
   if (WallpaperIsAlreadyLoaded(image, true /* compare_layouts */, layout)) {
     VLOG(1) << "Wallpaper is already loaded";
     return false;
   }
 
   current_wallpaper_.reset(new wallpaper::WallpaperResizer(
       image, GetMaxDisplaySizeInNative(), layout, task_runner_));
   current_wallpaper_->StartResize();
 
-  FOR_EACH_OBSERVER(WallpaperControllerObserver, observers_,
-                    OnWallpaperDataChanged());
+  for (auto& observer : observers_)
+    observer.OnWallpaperDataChanged();
   wallpaper_mode_ = WALLPAPER_IMAGE;
   InstallDesktopControllerForAllWindows();
   return true;
 }
 
 void WallpaperController::CreateEmptyWallpaper() {
   current_wallpaper_.reset();
   wallpaper_mode_ = WALLPAPER_IMAGE;
   InstallDesktopControllerForAllWindows();
 }
@@ skipping 150 matching lines @@
   return locked ? kShellWindowId_LockScreenWallpaperContainer
                 : kShellWindowId_WallpaperContainer;
 }
 
 void WallpaperController::UpdateWallpaper(bool clear_cache) {
   current_wallpaper_.reset();
   WmShell::Get()->wallpaper_delegate()->UpdateWallpaper(clear_cache);
 }
 
 }  // namespace ash