Reland r242290, r241609, r242134.

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

+// Copyright 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 CHROME_BROWSER_UI_WEBUI_SIGNIN_INLINE_LOGIN_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_SIGNIN_INLINE_LOGIN_HANDLER_H_
+
+#include "content/public/browser/web_ui_message_handler.h"
+
+// The base class handler for the inline login WebUI.
+class InlineLoginHandler : public content::WebUIMessageHandler {
+ public:
+  InlineLoginHandler();
+  virtual ~InlineLoginHandler();
+
+  // content::WebUIMessageHandler overrides:
+  virtual void RegisterMessages() OVERRIDE;
+
+ protected:
+  // Enum for gaia auth mode, must match AuthMode defined in
+  // chrome/browser/resources/gaia_auth_host/gaia_auth_host.js.
+  enum AuthMode {
+    kDefaultAuthMode = 0,
+    kOfflineAuthMode = 1,
+    kInlineAuthMode = 2
+  };
+
+ private:
+  // JS callback to initialize the gaia auth extension. It calls
+  // |SetExtraInitParams| to set extra init params.
+  void HandleInitializeMessage(const base::ListValue* args);
+  // JS callback to complete login. It calls |CompleteLogin| to do the real
+  // work.
+  void HandleCompleteLoginMessage(const base::ListValue* args);
+
+  virtual void SetExtraInitParams(base::DictionaryValue& params) {}
+  virtual void CompleteLogin(const base::ListValue* args) = 0;
+
+  DISALLOW_COPY_AND_ASSIGN(InlineLoginHandler);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_INLINE_LOGIN_HANDLER_H_