[Android WebView] Migrate the rendering code to a separate set of classes.

android_webview/browser/renderer_host/view_renderer_host.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 ANDROID_WEBVIEW_BROWSER_RENDER_HOST_VIEW_RENDERER_HOST_H_
+#define ANDROID_WEBVIEW_BROWSER_RENDER_HOST_VIEW_RENDERER_HOST_H_
+
+#include "base/threading/non_thread_safe.h"
+#include "content/public/browser/web_contents_observer.h"
+
+namespace android_webview {
+
+// Provides RenderViewHost wrapper functionality for sending WebView-specific
+// IPC messages to the renderer and from there to WebKit.
+class ViewRendererHost : public content::WebContentsObserver,
+                         public base::NonThreadSafe {
+ public:
+  class Client {
+   public:
+    virtual void OnPictureUpdated(int process_id, int render_view_id) = 0;
+
+   protected:
+    virtual ~Client() {}
+  };
+
+  ViewRendererHost(content::WebContents* contents, Client* client);
+  virtual ~ViewRendererHost();
+
+  // Captures the latest available picture pile synchronously.
+  void CapturePictureSync();
+
+  // Enables updating picture piles on every new frame.
+  // OnPictureUpdated is called when a new picture is available,
+  // stored by renderer id in RendererPictureMap.
+  void EnableCapturePictureCallback(bool enabled);
+
+  using content::WebContentsObserver::Observe;
+
+ private:
+  // content::WebContentsObserver implementation.
+  virtual void RenderViewGone(base::TerminationStatus status) OVERRIDE;
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+  void OnPictureUpdated();
+  bool IsRenderViewReady() const;
+
+  Client* client_;
+};
+
+}  // namespace android_webview
+
+#endif  // ANDROID_WEBVIEW_BROWSER_RENDER_HOST_VIEW_RENDERER_HOST_H_