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

chrome/browser/android/webapps/add_to_homescreen_data_fetcher.h

 // Copyright 2015 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_WEBAPPS_ADD_TO_HOMESCREEN_DATA_FETCHER_H_
 #define CHROME_BROWSER_ANDROID_WEBAPPS_ADD_TO_HOMESCREEN_DATA_FETCHER_H_
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/task/cancelable_task_tracker.h"
@@ skipping 26 matching lines @@
       public content::WebContentsObserver {
  public:
   class Observer {
    public:
     // Called when the title of the page is available.
     virtual void OnUserTitleAvailable(const base::string16& title) = 0;
 
     // Converts the icon into one that can be used on the Android Home screen.
     // |is_generated| is an out-param that indicates whether the icon was
     // generated by Chrome.
-    virtual SkBitmap FinalizeLauncherIcon(const SkBitmap& icon,
-                                          const GURL& url,
-                                          bool* is_generated) = 0;
+    virtual SkBitmap FinalizeLauncherIconInBackground(const SkBitmap& icon,
+                                                      const GURL& url,
+                                                      bool* is_generated) = 0;
 
     // Called when all the data needed to create a shortcut is available.
     virtual void OnDataAvailable(const ShortcutInfo& info,
                                  const SkBitmap& icon) = 0;
   };
 
   // Initialize the fetcher by requesting the information about the page to the
   // renderer process. The initialization is asynchronous and
   // OnDidGetWebApplicationInfo is expected to be called when finished.
   AddToHomescreenDataFetcher(content::WebContents* web_contents,
@@ skipping 24 matching lines @@
   bool OnMessageReceived(const IPC::Message& message) override;
 
  private:
   ~AddToHomescreenDataFetcher() override;
 
   // Grabs the favicon for the current URL.
   void FetchFavicon();
   void OnFaviconFetched(
       const favicon_base::FaviconRawBitmapResult& bitmap_result);
 
-  // Creates the launcher icon from the given bitmap.
-  void CreateLauncherIcon(
+  // Creates the launcher icon from the given bitmap and page URL. The page URL
+  // is used to generate an icon if there is no bitmap in |bitmap_result| or the
+  // bitmap is not large enough.
+  void CreateLauncherIconInBackground(
+      const GURL& page_url,
       const favicon_base::FaviconRawBitmapResult& bitmap_result);
 
   // Callback run after an attempt to download manifest icon has been made. May
   // kick off the download of a favicon if it failed (i.e. the bitmap is empty).
   void OnManifestIconFetched(const GURL& icon_url, const SkBitmap& icon);
 
   // Notifies the observer that the shortcut data is all available.
-  void NotifyObserver(const SkBitmap& icon);
+  void NotifyObserver(const GURL& icon_url, const SkBitmap& icon);
 
   // Looks up the original, online URL of the site requested.  The URL from the
   // WebContents may be an offline page or a distilled article which is not
   // appropriate for a home screen shortcut.
   GURL GetShortcutUrl(const GURL& original_url);
 
   Observer* weak_observer_;
 
   bool is_waiting_for_web_application_info_;
   bool is_icon_saved_;
   bool is_ready_;
   base::Timer icon_timeout_timer_;
   ShortcutInfo shortcut_info_;
   GURL splash_screen_url_;
 
   // The icon must only be set on the UI thread for thread safety.
   SkBitmap shortcut_icon_;
   base::CancelableTaskTracker favicon_task_tracker_;
 
   const int ideal_icon_size_in_dp_;
   const int minimum_icon_size_in_dp_;
   const int ideal_splash_image_size_in_dp_;
   const int minimum_splash_image_size_in_dp_;
 
   friend class base::RefCounted<AddToHomescreenDataFetcher>;
   DISALLOW_COPY_AND_ASSIGN(AddToHomescreenDataFetcher);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_WEBAPPS_ADD_TO_HOMESCREEN_DATA_FETCHER_H_