Refactor GuestView.

chrome/browser/guest_view/guest_view.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_GUEST_VIEW_GUEST_VIEW_H_
+#define CHROME_BROWSER_GUEST_VIEW_GUEST_VIEW_H_
+
+#include "chrome/browser/guest_view/guest_view_base.h"
+
+template <typename T>
+class GuestView : public GuestViewBase {
+ public:
+  static T* From(int embedder_process_id, int guest_instance_id) {
+    GuestViewBase* guest =
+        GuestViewBase::From(embedder_process_id, guest_instance_id);
+    if (!guest)
+      return NULL;
+    return guest->As<T>();
+  }
+
+  static T* FromWebContents(content::WebContents* contents) {
+    GuestViewBase* guest = GuestViewBase::FromWebContents(contents);
+    return guest ? guest->As<T>() : NULL;
+  }
+
+  // GuestViewBase implementation.
+  virtual const std::string& GetViewType() const OVERRIDE { return type_; }
+
+ protected:
+  GuestView(content::WebContents* guest_web_contents,
+            const std::string& embedder_extension_id)
+      : GuestViewBase(guest_web_contents, embedder_extension_id),
+        type_(T::Type) {}
+
+ private:
+  std::string type_;
+  DISALLOW_COPY_AND_ASSIGN(GuestView);
+};
+
+#endif  // CHROME_BROWSER_GUEST_VIEW_GUEST_VIEW_H_