Added implementation of SyncEventObserver to route events to Javascript Extension.

chrome/browser/extensions/api/sync_file_system/extension_sync_event_observer.h

+// 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_API_SYNC_FILE_SYSTEM_EXTENSION_SYNC_EVENT_OBSERVER_
+#define CHROME_BROWSER_EXTENSIONS_API_SYNC_FILE_SYSTEM_EXTENSION_SYNC_EVENT_OBSERVER_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "chrome/browser/sync_file_system/sync_event_observer.h"
+
+class Profile;
+
+namespace extensions {
+
+// Handles sending JavaScript events to exactly one extension ID.

[kinuko, 2012/11/28 11:06:40]

nit: 'exactly one' may not be correct if we get broadcasting events?

[calvinlo, 2012/11/28 12:26:34]

Sorry forgot to update this. You are correct as there is no longer going to be a
manager.

+class ExtensionSyncEventObserver
+    : public sync_file_system::SyncEventObserver {
+ public:
+  ExtensionSyncEventObserver(Profile* profile,
+                             const std::string& service_name);
+  ~ExtensionSyncEventObserver();
+
+  virtual void OnSyncStateUpdated(
+      const GURL& app_origin,
+      sync_file_system::SyncEventObserver::SyncServiceState state,
+      const std::string& description) OVERRIDE;
+
+  virtual void OnFileSynced(fileapi::SyncOperationType operation,
+                            const fileapi::FileSystemURL& url) OVERRIDE;
+
+ private:
+   Profile* profile_;
+   const std::string service_name_;
+
+   const std::string GetExtensionId(const GURL& app_origin);
+
+   DISALLOW_COPY_AND_ASSIGN(ExtensionSyncEventObserver);
+};
+
+}  // namespace extensions
+
+#endif  // #ifndef CHROME_BROWSER_EXTENSIONS_API_SYNC_FILE_SYSTEM_EXTENSION_SYNC_EVENT_OBSERVER_