Implement the new Sync Confirmation dialog on Linux and Windows.

chrome/browser/ui/webui/signin/sync_confirmation_handler.h

Index: chrome/browser/ui/webui/signin/sync_confirmation_handler.h
diff --git a/chrome/browser/ui/webui/signin/sync_confirmation_handler.h b/chrome/browser/ui/webui/signin/sync_confirmation_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..ba44e904da2d648ed83b6b6d4209d549fdec45dd
--- /dev/null
+++ b/chrome/browser/ui/webui/signin/sync_confirmation_handler.h
@@ -0,0 +1,35 @@
+// Copyright 2015 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_UI_WEBUI_SIGNIN_SYNC_CONFIRMATION_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_SIGNIN_SYNC_CONFIRMATION_HANDLER_H_
+
+#include "base/macros.h"
+#include "base/values.h"
+#include "components/signin/core/browser/account_tracker_service.h"
+#include "content/public/browser/web_ui_message_handler.h"
+
+class SyncConfirmationHandler : public content::WebUIMessageHandler,
+                                public AccountTrackerService::Observer {
+ public:
+  SyncConfirmationHandler();
+  ~SyncConfirmationHandler() override;
+
+  void RegisterMessages() override;
+
+  // AccountTrackerService::Observer:
+  void OnAccountUpdated(const AccountInfo& info) override;
+
+ private:
+  void HandleConfirmMessage(const base::ListValue* args);
+  void HandleUndoMessage(const base::ListValue* args);
+  void HandleInitializedMessage(const base::ListValue* args);
+  void HandleGoToSettingsMessage(const base::ListValue* args);
+
+  void SetUserImageURL(std::string url);
+
+  DISALLOW_COPY_AND_ASSIGN(SyncConfirmationHandler);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_SYNC_CONFIRMATION_HANDLER_H_