[SyncFS] Add TaskLogger and wire up it.

chrome/browser/sync_file_system/drive_backend/sync_task_manager.cc

 // Copyright 2014 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/sync_file_system/drive_backend/sync_task_manager.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/sync_file_system/drive_backend/sync_task_token.h"
@@ skipping 172 matching lines @@
 
   DVLOG(3) << "NotifyTaskDone: " << "finished with status=" << status
            << " (" << SyncStatusCodeToString(status) << ")"
            << " " << token_->location().ToString();
 
   if (token->blocking_factor()) {
     dependency_manager_.Erase(token->blocking_factor());
     token->clear_blocking_factor();
   }
 
+  // TODO(tzik): Record TaskLog to |client_| here.
+
   scoped_ptr<SyncTask> task;
   SyncStatusCallback callback = token->callback();
   token->clear_callback();
   if (token->token_id() == SyncTaskToken::kForegroundTaskTokenID) {
     token_ = token.Pass();
     task = running_foreground_task_.Pass();
   } else {
     task = running_background_tasks_.take_and_erase(token->token_id());
   }
 
@@ skipping 129 matching lines @@
     closure.Run();
     return;
   }
 
   if (client_)
     client_->MaybeScheduleNextTask();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system