Media Galleries API Picasa: Make PicasaDataProvider handle async PMP and INI parsing robustly.

chrome/browser/media_galleries/fileapi/safe_picasa_albums_indexer.cc

 // 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.
 
 #include "chrome/browser/media_galleries/fileapi/safe_picasa_albums_indexer.h"
 
 #include "base/file_util.h"
 #include "chrome/browser/media_galleries/fileapi/media_file_system_backend.h"
 #include "chrome/common/chrome_utility_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/child_process_data.h"
-#include "content/public/browser/utility_process_host.h"
 
 using chrome::MediaFileSystemBackend;
 using content::BrowserThread;
 using content::UtilityProcessHost;
 
 namespace picasa {
 
 namespace {
 
 // Picasa INI files are named "picasa.ini" on Picasa for Windows before version
@@ skipping 75 matching lines @@
         BrowserThread::IO,
         FROM_HERE,
         base::Bind(&SafePicasaAlbumsIndexer::StartWorkOnIOThread, this));
   }
 }
 
 void SafePicasaAlbumsIndexer::StartWorkOnIOThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK_EQ(FINISHED_READING_INI_FILES_STATE, parser_state_);
 
-  UtilityProcessHost* host =
-      UtilityProcessHost::Create(this, base::MessageLoopProxy::current());
-  host->EnableZygote();
-  host->Send(new ChromeUtilityMsg_IndexPicasaAlbumsContents(album_uids_,
-                                                            folders_inis_));
+  utility_process_host_ = content::UtilityProcessHost::Create(
+      this,
+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO).get())
+      ->AsWeakPtr();
+
+  utility_process_host_->EnableZygote();
+  utility_process_host_->Send(new ChromeUtilityMsg_IndexPicasaAlbumsContents(
+      album_uids_, folders_inis_));
   parser_state_ = STARTED_PARSING_STATE;
 }
 
 void SafePicasaAlbumsIndexer::OnIndexPicasaAlbumsContentsFinished(
     const AlbumImagesMap& albums_images) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (parser_state_ != STARTED_PARSING_STATE)
     return;
 
   MediaFileSystemBackend::MediaTaskRunner()->PostTask(
       FROM_HERE,
-      base::Bind(callback_, albums_images));
+      base::Bind(callback_,
+                 make_scoped_refptr(this),
+                 albums_images));
   parser_state_ = FINISHED_PARSING_STATE;
 }
 
 void SafePicasaAlbumsIndexer::OnProcessCrashed(int exit_code) {
   OnIndexPicasaAlbumsContentsFinished(AlbumImagesMap());
 }
 
 bool SafePicasaAlbumsIndexer::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(SafePicasaAlbumsIndexer, message)
     IPC_MESSAGE_HANDLER(
         ChromeUtilityHostMsg_IndexPicasaAlbumsContents_Finished,
         OnIndexPicasaAlbumsContentsFinished)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 }  // namespace picasa