gdata: Convert FindEntryByResourceIdSync() to asynchronous.

chrome/browser/chromeos/gdata/gdata_file_system.cc

 // Copyright (c) 2012 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/chromeos/gdata/gdata_file_system.h"
 
 #include <errno.h>
 #include <sys/stat.h>
 
 #include <set>
@@ skipping 814 matching lines @@
 };
 
 // Returns callback which runs the given |callback| on the current thread.
 template<typename CallbackType>
 CallbackType CreateRelayCallback(const CallbackType& callback) {
   return base::Bind(&RelayCallback<CallbackType>::Run,
                     base::MessageLoopProxy::current(),
                     callback);
 }
 
+// Callback used to find a directory element for file system updates.
+void ReadOnlyFindEntryCallback(GDataEntry** out,
+                               base::PlatformFileError error,
+                               GDataEntry* entry) {
+  if (error == base::PLATFORM_FILE_OK)
+    *out = entry;
+}
+
 }  // namespace
 
 // GDataFileSystem::GetDocumentsParams struct implementation.
 
 GDataFileSystem::GetDocumentsParams::GetDocumentsParams(
     int start_changestamp,
     int root_feed_changestamp,
     std::vector<DocumentFeed*>* feed_list,
     bool should_fetch_multiple_feeds,
     const FilePath& search_file_path,
@@ skipping 196 matching lines @@
   update_timer_.Stop();
 }
 
 void GDataFileSystem::Authenticate(const AuthStatusCallback& callback) {
   // TokenFetcher, used in DocumentsService, must be run on UI thread.
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   documents_service_->Authenticate(callback);
 }
 
-void GDataFileSystem::FindEntryByResourceIdSync(
+void GDataFileSystem::FindEntryByResourceId(const std::string& resource_id,
+                                            const FindEntryCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
+         BrowserThread::CurrentlyOn(BrowserThread::IO));
+  RunTaskOnUIThread(
+      base::Bind(&GDataFileSystem::FindEntryByResourceIdOnUIThread,
+                 ui_weak_ptr_,
+                 resource_id,
+                 CreateRelayCallback(callback)));
+}
+
+void GDataFileSystem::FindEntryByResourceIdOnUIThread(
     const std::string& resource_id,
     const FindEntryCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
   base::AutoLock lock(lock_);  // To access root.
-
   GDataFile* file = NULL;
   GDataEntry* entry = root_->GetEntryByResourceId(resource_id);
   if (entry)
     file = entry->AsGDataFile();
 
   if (file)
     callback.Run(base::PLATFORM_FILE_OK, file);
   else
     callback.Run(base::PLATFORM_FILE_ERROR_NOT_FOUND, NULL);
 }
@@ skipping 4118 matching lines @@
     base::PlatformFileError error,
     const std::string& resource_id,
     const std::string& md5) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (!callback.is_null())
     callback.Run(error);
 }
 
 }  // namespace gdata