Calls ShortcutHelper::FinalizeLauncherIcon() on worker thread instead of on 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 <jni.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
@@ skipping 67 matching lines @@
 
   if (add_shortcut_pending_)
     AddShortcut(info, icon);
 }
 
 void AddToHomescreenDialogHelper::Destroy(JNIEnv* env,
                                           const JavaParamRef<jobject>& obj) {
   delete this;
 }
 
-SkBitmap AddToHomescreenDialogHelper::FinalizeLauncherIcon(
+SkBitmap AddToHomescreenDialogHelper::FinalizeLauncherIconInBackground(
       const SkBitmap& bitmap,

[dominickn, 2016/08/08 03:13:42]

Nit: I think this indentation is wrong, you may as well fix it while you're here
if that's the case. :)

       const GURL& url,
       bool* is_generated) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(content::BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
 
-  return ShortcutHelper::FinalizeLauncherIcon(bitmap, url, is_generated);
+  return ShortcutHelper::FinalizeLauncherIconInBackground(bitmap, url,
+                                                          is_generated);
 }
 
 void AddToHomescreenDialogHelper::AddShortcut(
     JNIEnv* env,
     const JavaParamRef<jobject>& obj,
     const JavaParamRef<jstring>& j_user_title) {
   add_shortcut_pending_ = true;
 
   base::string16 user_title =
       base::android::ConvertJavaStringToUTF16(env, j_user_title);
@@ skipping 39 matching lines @@
   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());
 }