Android WebView: post QuotaManager calls to UI thread.

android_webview/browser/aw_quota_manager_bridge.h

 // Copyright (c) 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.
 
 #ifndef ANDROID_WEBVIEW_BROWSER_AW_QUOTA_MANAGER_BRIDGE_H_
 #define ANDROID_WEBVIEW_BROWSER_AW_QUOTA_MANAGER_BRIDGE_H_
 
+#include "base/memory/ref_counted.h"
+
 namespace android_webview {
 
-// Empty base class so this can be owned and destroyed by AwBrowserContext.
-class AwQuotaManagerBridge {
- public:
+// Empty base class so this can be refcounted by AwBrowserContext.
+class AwQuotaManagerBridge :
+    public base::RefCountedThreadSafe<AwQuotaManagerBridge> {
+ protected:
+  friend class base::RefCountedThreadSafe<AwQuotaManagerBridge>;
+  AwQuotaManagerBridge();
   virtual ~AwQuotaManagerBridge();
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_AW_QUOTA_MANAGER_BRIDGE_H_