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

chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc

Index: chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc
diff --git a/chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc b/chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc
index 0ffe0adf17e0b10b6f999a73923cb72753a5f130..a629d3df976cd2899a8965eb1eb21d7fd2e53307 100644
--- a/chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc
+++ b/chrome/browser/android/webapps/add_to_homescreen_data_fetcher.cc
@@ -211,19 +211,17 @@ void AddToHomescreenDataFetcher::OnFaviconFetched(
   if (!web_contents() || !weak_observer_ || is_icon_saved_)
     return;
 
-  content::BrowserThread::PostTask(
-      content::BrowserThread::IO,
+  content::BrowserThread::PostBlockingPoolTask(

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

I'm not sure if creating a launcher icon should block shutdown. Perhaps
content::BrowserThread::GetBlockingPool()->PostWorkerTask(... SKIP_ON_SHUTDOWN)?
Not overly fussed either way though.

[gone, 2016/08/08 17:14:11]

If you're thinking about shutdown on Android, we don't actually _have_ a clean
shutdown procedure: Android just kills the process when it feels like and we
don't get a reliable signal about it.  Not sure of the value of switching to the
Blocking thing, though I'm not familiar with the call.

       FROM_HERE,
-      base::Bind(&AddToHomescreenDataFetcher::CreateLauncherIcon,
-                 this,
-                 bitmap_result));
+      base::Bind(&AddToHomescreenDataFetcher::CreateLauncherIconInBackground,
+                 this, bitmap_result));
 }
 
-void AddToHomescreenDataFetcher::CreateLauncherIcon(
+void AddToHomescreenDataFetcher::CreateLauncherIconInBackground(
     const favicon_base::FaviconRawBitmapResult& bitmap_result) {
   if (!web_contents() || !weak_observer_) return;
 
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  DCHECK(content::BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
   SkBitmap icon_bitmap;
   if (bitmap_result.is_valid()) {
     gfx::PNGCodec::Decode(bitmap_result.bitmap_data->front(),
@@ -233,9 +231,8 @@ void AddToHomescreenDataFetcher::CreateLauncherIcon(
 
   bool is_generated = false;
   if (weak_observer_) {
-    icon_bitmap = weak_observer_->FinalizeLauncherIcon(icon_bitmap,
-                                                       shortcut_info_.url,
-                                                       &is_generated);
+    icon_bitmap = weak_observer_->FinalizeLauncherIconInBackground(
+        icon_bitmap, shortcut_info_.url, &is_generated);
   }
 
   shortcut_info_.icon_url = is_generated ? GURL() : bitmap_result.icon_url;