Calls ShortcutHelper::FinalizeLauncherIcon() on worker thread instead of on IO thread

chrome/browser/android/shortcut_helper.h

 // Copyright 2013 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_ANDROID_SHORTCUT_HELPER_H_
 #define CHROME_BROWSER_ANDROID_SHORTCUT_HELPER_H_
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_weak_ref.h"
 #include "base/callback_forward.h"
@@ skipping 84 matching lines @@
                                      const std::string& webapp_id);
 
   // Stores the webapp splash screen in the WebappDataStorage associated with
   // |webapp_id|.
   static void StoreWebappSplashImage(const std::string& webapp_id,
                                      const SkBitmap& splash_image);
 
   // Returns the given icon, modified to match the launcher requirements.
   // This method may generate an entirely new icon; if this is the case,
   // |is_generated| will be set to |true|.
-  static SkBitmap FinalizeLauncherIcon(const SkBitmap& icon,
-                                       const GURL& url,
-                                       bool* is_generated);
+  // Must not be called on the UI thread.

[dominickn, 2016/08/08 03:13:41]

Nit: "Must be called on a background worker thread." would be more accurate I
think, since it DCHECKs this.

+  static SkBitmap FinalizeLauncherIconInBackground(const SkBitmap& icon,
+                                                   const GURL& url,
+                                                   bool* is_generated);
 
   // Returns true if WebAPKs are enabled and there is a WebAPK installed which
   // can handle |url|.
   static bool IsWebApkInstalled(const GURL& url);
 
  private:
   ShortcutHelper() = delete;
   ~ShortcutHelper() = delete;
 
   DISALLOW_COPY_AND_ASSIGN(ShortcutHelper);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_SHORTCUT_HELPER_H_