Added implementation of SyncEventObserver to route events to Javascript Extension.

chrome/browser/extensions/api/sync_file_system/extension_sync_event_observer.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/extensions/api/sync_file_system/extension_sync_event_observer.h"
+#include "chrome/browser/extensions/event_names.h"
+#include "chrome/browser/extensions/event_router.h"
+#include "chrome/browser/extensions/extension_system.h"
+#include "chrome/browser/sync_file_system/sync_event_observer.h"
+#include "chrome/common/extensions/api/sync_file_system.h"
+
+using sync_file_system::SyncEventObserver;
+
+namespace extensions {
+
+namespace {
+
+api::sync_file_system::SyncStateStatus SyncServiceStateEnumToExtensionEnum(
+    SyncEventObserver::SyncServiceState state) {
+  switch(state) {
+    case SyncEventObserver::SYNC_SERVICE_RUNNING:
+      return api::sync_file_system::SYNC_FILE_SYSTEM_SYNC_STATE_STATUS_RUNNING;
+    case SyncEventObserver::SYNC_SERVICE_AUTHENTICATION_REQUIRED:
+      return api::sync_file_system::
+          SYNC_FILE_SYSTEM_SYNC_STATE_STATUS_AUTHENTICATION_REQUIRED;
+    case SyncEventObserver::SYNC_SERVICE_TEMPORARY_UNAVAILABLE:
+      return api::sync_file_system::
+          SYNC_FILE_SYSTEM_SYNC_STATE_STATUS_TEMPORARY_UNAVAILABLE;
+    case SyncEventObserver::SYNC_SERVICE_DISABLED:
+      return api::sync_file_system::SYNC_FILE_SYSTEM_SYNC_STATE_STATUS_DISABLED;
+  }
+  NOTREACHED();
+  return api::sync_file_system::SYNC_FILE_SYSTEM_SYNC_STATE_STATUS_NONE;
+}
+
+}  // namespace
+
+ExtensionSyncEventObserver::ExtensionSyncEventObserver(
+    Profile* profile,
+    const std::string& service_name)
+    : profile_(profile),
+      service_name_(service_name) {}
+
+void ExtensionSyncEventObserver::OnSyncStateUpdated(
+    const std::string& extension_id,

[kinuko, 2012/11/28 07:41:13]

This is given as GURL right?

I think you can get the app or extension for given GURL by doing something like
this (please look for the original definition for more details):

Extension* app =
ExtensionSystem::Get(profile_)->extension_service()->GetInstalledApp(app_origin);

Extension class has id() accessor. (Please DCHECK before accessing it)

[calvinlo, 2012/11/28 10:43:46]

Done.

+    sync_file_system::SyncEventObserver::SyncServiceState state,
+    const std::string& description) {
+  // TODO(calvinlo): Check extension in set of extension_ids that are listening
+  // for events. If extension_id is not in the set, then ignore the event.
+
+  // Convert state and description into SyncState Object
+  api::sync_file_system::SyncState sync_state;
+  sync_state.service_name = "drive";

[kinuko, 2012/11/28 07:41:13]

sync_state.service_name = service_name_; ?

[calvinlo, 2012/11/28 10:43:46]

Done. Sorry my mistake.

+  sync_state.state = SyncServiceStateEnumToExtensionEnum(state);
+  sync_state.description = description;
+  scoped_ptr<base::ListValue> params(
+      api::sync_file_system::OnSyncStateChanged::Create(sync_state));
+
+  // Dispatch the event to the extension
+  ExtensionSystem::Get(profile_)->event_router()->DispatchEventToExtension(
+      extension_id, event_names::kOnSyncStateChanged, params.Pass(),
+      profile_, GURL());
+}
+
+}  // namespace extensions