Re-implement form validation message UI with native widgets. (Common and Mac)

chrome/renderer/validation_message_agent.h

+// Copyright (c) 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_RENDERER_VALIDATION_MESSAGE_AGENT_H_
+#define CHROME_RENDERER_VALIDATION_MESSAGE_AGENT_H_
+
+#include "content/public/renderer/render_view_observer.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebValidationMessageClient.h"
+
+namespace content {
+class RenderView;
+}
+
+class ValidationMessageAgent : public content::RenderViewObserver,
+                               public WebKit::WebValidationMessageClient {
+ public:
+  explicit ValidationMessageAgent(content::RenderView* render_view);
+  virtual ~ValidationMessageAgent();
+
+ private:
+  // WebValidationMessageClient functions:
+  virtual void showValidationMessage(const WebKit::WebRect& anchor_in_screen,
+                                     const WebKit::WebString& main_text,
+                                     const WebKit::WebString& sub_text,
+                                     WebKit::WebTextDirection hint) OVERRIDE;
+  virtual void hideValidationMessage() OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(ValidationMessageAgent);
+};
+
+#endif  // CHROME_RENDERER_VALIDATION_MESSAGE_AGENT_H_