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..54f63c5d915fd5c561fd259117c72752573448fe
--- /dev/null
+++ b/chrome/browser/ui/webui/signin/sync_confirmation_handler.h
@@ -0,0 +1,56 @@
+// 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_
+

[Dan Beam, 2016/01/13 23:45:22]

nit: #include <string>

[anthonyvd, 2016/01/18 21:40:08]

Done.

+#include "base/macros.h"
+#include "components/signin/core/browser/account_tracker_service.h"
+#include "content/public/browser/web_ui_message_handler.h"
+
+namespace base {
+class ListValue;
+}
+
+class SyncConfirmationHandler : public content::WebUIMessageHandler,
+                                public AccountTrackerService::Observer {
+ public:
+  SyncConfirmationHandler();
+  ~SyncConfirmationHandler() override;
+
+  // content::WebUIMessageHandler:
+  void RegisterMessages() override;
+
+  // AccountTrackerService::Observer:
+  void OnAccountUpdated(const AccountInfo& info) override;
+
+ private:
+  // Handles "confirm" message from the page. No arguments.
+  // This message is sent when the user confirms that they want complete sign in
+  // with default sync settings.
+  void HandleConfirm(const base::ListValue* args);
+
+  // Handles "undo" message from the page. No arguments.
+  // This message is sent when the user clicks "undo" on the sync confirmation
+  // dialog, which aborts signin and prevents sync from starting.
+  void HandleUndo(const base::ListValue* args);
+
+  // Handles "initialized" message from the page. No arguments.
+  // This message is sent when the sync confirmation dialog is finished being
+  // initialized.
+  void HandleInitialized(const base::ListValue* args);
+
+  // Handles "goToSettings" message from the page. No arguments.
+  // This message is sent when the user clicks on the "Settings" link in the
+  // sync confirmation dialog, which completes sign in but takes the user to the
+  // sync settings page for configuration before starting sync.
+  void HandleGoToSettings(const base::ListValue* args);
+
+  // Sets the profile picture shown in the dialog to the image at |url|

[Dan Beam, 2016/01/13 23:45:22]

nit: end with .

[anthonyvd, 2016/01/18 21:40:08]

Done.

+  void SetUserImageURL(const std::string& url);
+
+  DISALLOW_COPY_AND_ASSIGN(SyncConfirmationHandler);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_SYNC_CONFIRMATION_HANDLER_H_