Implemented Browser Plugin (NOT FOR REVIEW)

content/renderer/browser_plugin/browser_plugin.h

+// Copyright (c) 2012 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_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_H_
+#define CONTENT_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_H_
+#pragma once
+
+#include "base/process.h"
+#include "content/renderer/render_view_impl.h"
+#include "ipc/ipc_channel_handle.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebPluginParams.h"
+#include "ui/gfx/size.h"
+#include "webkit/plugins/webview_plugin.h"
+
+namespace content {
+class RenderView;
+}
+
+namespace WebKit {
+class WebPlugin;
+}
+
+// A browser plugin is a plugin container that hosts an out-of-process "guest"
+// RenderView. Loading up a new process, creating a new RenderView, navigating
+// to a given URL, and establishing a guest-to-embedder channel can take
+// hundreds of milliseconds. Furthermore, a RenderView's associated browser-side
+// WebContents, RenderViewHost, and SiteInstance must be created and accessed on
+// the UI thread of the browser process.
+//
+// To avoid blocking the embedder RenderView and to avoid introducing the
+// potential for deadlock, BrowserPlugin attaches a placeholder that takes
+// place of the guest RenderView until the guest has established a connection
+// with its embedder RenderView. This permits asynchronously loading of the
+// guest while the embedder RenderView is permitted to continue to receive and
+// process events.
+//
+// Furthermore, certain navigations can swap to a new guest RenderView on an
+// different process. BrowserPlugin is the consistent facade that the embedder's
+// WebKit instance talks to regardless of which process it's communicating with.
+class BrowserPlugin {
+ public:
+  // Creates a new WebViewPlugin with a BrowserPlugin as a delegate.
+  static WebKit::WebPlugin* Create(
+      RenderViewImpl* render_view,
+      WebKit::WebFrame* frame,
+      const WebKit::WebPluginParams& params);
+
+  static BrowserPlugin* FromID(int id);
+
+  webkit::WebViewPlugin* placeholder() { return placeholder_; }
+
+  webkit::ppapi::WebPluginImpl* plugin() { return plugin_; }
+
+  const WebKit::WebPluginParams& plugin_params() const {
+    return plugin_params_;
+  }
+
+  void LoadGuest(int guest_process_id,
+                 const IPC::ChannelHandle& channel_handle);
+
+  RenderViewImpl* render_view() { return render_view_; }
+
+ private:
+  BrowserPlugin(RenderViewImpl* render_view,
+                WebKit::WebFrame* frame,
+                const WebKit::WebPluginParams& params,
+                const std::string& html_data);
+  virtual ~BrowserPlugin();
+
+  // Parses the width, height, and source URL of the browser plugin
+  // from the element's attributes and outputs them to size and src. If not
+  // found, it uses the defaults specified here as parameters.
+  void ParsePluginParameters(int default_width, int default_height,
+                             const std::string& default_src,
+                             gfx::Size* size,
+                             std::string* src);
+  // Replace the current guest with a new guest.
+  void Replace(webkit::ppapi::WebPluginImpl* new_plugin);
+
+  RenderViewImpl* render_view_;
+  WebKit::WebPluginParams plugin_params_;
+  webkit::WebViewPlugin* placeholder_;
+  webkit::ppapi::WebPluginImpl* plugin_;
+  int id_;
+
+  DISALLOW_COPY_AND_ASSIGN(BrowserPlugin);
+};
+
+#endif  // CONTENT_RENDERER_BROWSER_PLUGIN_BROWSER_PLUGIN_H_