Run ShortcutHelper::AddToLauncherInBackgroundWithSkBitmap() on Worker thread instead of IO thread

chrome/browser/android/webapps/add_to_homescreen_dialog_helper.cc

 // 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.
 
 #include "chrome/browser/android/webapps/add_to_homescreen_dialog_helper.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/guid.h"
 #include "base/location.h"
@@ skipping 103 matching lines @@
     return;
   add_shortcut_pending_ = false;
 
   content::WebContents* web_contents = data_fetcher_->web_contents();
   if (!web_contents)
     return;
 
   RecordAddToHomescreen();
 
   const std::string& uid = base::GenerateGUID();
-  content::BrowserThread::PostTask(
-      content::BrowserThread::IO, FROM_HERE,
-      base::Bind(&ShortcutHelper::AddToLauncherInBackgroundWithSkBitmap,
-                 web_contents->GetBrowserContext(), info, uid, icon,
-                 data_fetcher_->FetchSplashScreenImageCallback(uid)));
+  ShortcutHelper::AddToLauncherWithSkBitmap(
+      web_contents->GetBrowserContext(), info, uid, icon,
+      data_fetcher_->FetchSplashScreenImageCallback(uid));
 }
 
 bool AddToHomescreenDialogHelper::RegisterAddToHomescreenDialogHelper(
       JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 void AddToHomescreenDialogHelper::RecordAddToHomescreen() {
   // Record that the shortcut has been added, so no banners will be shown
   // for this app.
   content::WebContents* web_contents = data_fetcher_->web_contents();
   if (!web_contents)
     return;
 
   AppBannerSettingsHelper::RecordBannerEvent(
       web_contents, web_contents->GetURL(),
       data_fetcher_->shortcut_info().url.spec(),
       AppBannerSettingsHelper::APP_BANNER_EVENT_DID_ADD_TO_HOMESCREEN,
       base::Time::Now());
 }