Always use arc::InstanceHolder<T>::GetInstanceForMethod

chrome/browser/chromeos/arc/arc_wallpaper_service.cc

 // 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.
 
 #include "chrome/browser/chromeos/arc/arc_wallpaper_service.h"
 
 #include <vector>
 
 #include "ash/common/wallpaper/wallpaper_controller.h"
 #include "ash/common/wm_shell.h"
@@ skipping 78 matching lines @@
   ImageDecoder::Cancel(this);
   ash::WallpaperController* wc = GetWallpaperController();
   if (wc)
     wc->RemoveObserver(this);
   arc_bridge_service()->wallpaper()->RemoveObserver(this);
 }
 
 void ArcWallpaperService::OnInstanceReady() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   mojom::WallpaperInstance* wallpaper_instance =
-      arc_bridge_service()->wallpaper()->instance();
-  if (!wallpaper_instance) {
-    LOG(DFATAL) << "OnWallpaperInstanceReady called, "
-                << "but no wallpaper instance found";
+      arc_bridge_service()->wallpaper()->GetInstanceForMethod("Init");
+  if (!wallpaper_instance)
     return;
-  }
   wallpaper_instance->Init(binding_.CreateInterfacePtrAndBind());
   ash::WmShell::Get()->wallpaper_controller()->AddObserver(this);
 }
 
 void ArcWallpaperService::OnInstanceClosed() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   ash::WallpaperController* wc = GetWallpaperController();
   if (wc)
     wc->RemoveObserver(this);
 }
@@ skipping 28 matching lines @@
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   auto* wallpaper_instance =
       arc_bridge_service()->wallpaper()->GetInstanceForMethod(
           "OnWallpaperChanged", kMinOnWallpaperChangedVersion);
   if (!wallpaper_instance)
     return;
   wallpaper_instance->OnWallpaperChanged();
 }
 
 }  // namespace arc