Move WebUIMessageHandler to its own file in the public directory and put it in the content namesp...

content/public/browser/web_ui_message_handler.h

+// Copyright (c) 2011 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 CONTENT_PUBLIC_BROWSER_WEB_UI_MESSAGE_HANDLER_H_
+#define CONTENT_PUBLIC_BROWSER_WEB_UI_MESSAGE_HANDLER_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/string16.h"
+#include "content/common/content_export.h"
+
+class GURL;
+class WebUI;
+class WebUIBrowserTest;
+
+namespace base {
+class DictionaryValue;
+class ListValue;
+}
+
+namespace content {
+
+// Messages sent from the DOM are forwarded via the WebUI to handler
+// classes. These objects are owned by WebUI and destroyed when the
+// host is destroyed.
+class CONTENT_EXPORT WebUIMessageHandler {
+ public:
+  WebUIMessageHandler() : web_ui_(NULL) {}
+  virtual ~WebUIMessageHandler() {}
+
+ protected:
+  // Helper methods:
+
+  // Adds "url" and "title" keys on incoming dictionary, setting title
+  // as the url as a fallback on empty title.
+  static void SetURLAndTitle(base::DictionaryValue* dictionary,
+                             string16 title,
+                             const GURL& gurl);
+
+  // Extract an integer value from a list Value.
+  static bool ExtractIntegerValue(const base::ListValue* value, int* out_int);
+
+  // Extract a floating point (double) value from a list Value.
+  static bool ExtractDoubleValue(const base::ListValue* value,
+                                 double* out_value);
+
+  // Extract a string value from a list Value.
+  static string16 ExtractStringValue(const base::ListValue* value);
+
+  // This is where subclasses specify which messages they'd like to handle and
+  // perform any additional initialization.. At this point web_ui() will return
+  // the associated WebUI object.
+  virtual void RegisterMessages() = 0;
+
+  // Returns the attached WebUI for this handler.
+  WebUI* web_ui() const { return web_ui_; }
+
+ private:
+  friend class ::WebUI;
+  friend class ::WebUIBrowserTest;
+
+  void set_web_ui(WebUI* web_ui) { web_ui_ = web_ui; }
+
+  WebUI* web_ui_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebUIMessageHandler);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_WEB_UI_MESSAGE_HANDLER_H_
+