Adding RenderWidgetHostViewChildFrame for OOPIF view.

content/browser/frame_host/cross_process_frame_connector.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 CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
+#define CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
+
+#include "cc/output/compositor_frame.h"
+#include "ui/gfx/rect.h"
+
+namespace IPC {
+class Message;
+}
+
+struct GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params;
+
+namespace content {
+class RenderFrameHostImpl;
+class RenderWidgetHostImpl;
+class RenderWidgetHostViewChildFrame;
+
+// CrossProcessFrameConnector provides the platform view abstraction for
+// RenderWidgetHostViewChildFrame allowing RWHVChildFrame to remain ignorant
+// of RenderFrameHost.
+//
+// The RenderWidgetHostView of an out-of-process child frame needs to
+// communicate with the swapped out RenderFrameHost representing this frame
+// in the process of the parent frame. For example, assume you have this page:
+//
+//   -----------------
+//   | frame 1       |
+//   |  -----------  |
+//   |  | frame 2 |  |
+//   |  -----------  |
+//   -----------------
+//
+// If frames 1 and 2 are in process A and B, there are 4 RenderFrameHosts:
+//   A1 - RFH for frame 1 in process A
+//   B1 - Swapped out RFH for frame 1 in process B
+//   A2 - Swapped out RFH for frame 2 in process A
+//   B2 - RFH for frame 2 in process B
+//
+// B2, having a parent frame in a diferent process, will have a
+// RenderWidgetHostViewChildFrame. This RenderWidgetHostViewChildFrame needs

[Charlie Reis, 2013/12/17 01:09:31]

nit: needs to

[awong, 2013/12/17 02:45:27]

Done.

+// communicate with A2 so that the painting logic in process A can composite
+// B2's data with A1's. CrossProcessFrameConnector bridges between B2 to A2

[Charlie Reis, 2013/12/17 01:09:31]

bridges between B2's RWHVChildFrame and A2

(or am I mistaken?)

[awong, 2013/12/17 02:45:27]

Good catch. Fixed.

+// to allow for this communiation. (Note B1 is only mentioned for completeness.

[nasko, 2013/12/17 00:56:52]

nit: communication

[awong, 2013/12/17 02:45:27]

Done.

+// It is not needed in this example.)
+//
+// CrossProcessFrameConnector objects are owned by the child frame's
+// RenderFrameHostManager. When a child frame swaps, SetChildFrameView() is
+// called to update to the new view.
+//
+// TODO(kenrb): Double-check this comment's accuracy.
+class CrossProcessFrameConnector {
+ public:
+  explicit CrossProcessFrameConnector(

[Charlie Reis, 2013/12/17 01:09:31]

Since you've spelled out the example so nicely above, can you add a comment here
saying this expects RFH A2 from the example?

[awong, 2013/12/17 02:45:27]

Done.

+      RenderFrameHostImpl* frame_proxy_in_parent_renderer);
+  virtual ~CrossProcessFrameConnector();
+
+  bool OnMessageReceived(const IPC::Message &msg);
+
+  void SetChildFrameView(RenderWidgetHostViewChildFrame* child_frame_view);
+
+  // 'Platform' functionality exposed to RenderWidgetHostViewChildFrame.
+  // These methods can forward messages to the child frame proxy in the parent
+  // frame renderer or attempt to handle them within the browser process.
+  void ChildFrameBuffersSwapped(
+      const GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params& params,
+      int gpu_host_id);
+
+  void ChildFrameCompositorFrameSwapped(
+      uint32 output_surface_id,
+      scoped_ptr<cc::CompositorFrame> frame);
+
+  gfx::Rect ChildFrameRect();
+
+ private:
+  // Handlers for messages received from the parent frame.
+  void OnBuffersSwappedACK(std::string mailbox_name,
+                           int route_id,
+                           int gpu_host_id,
+                           uint32 sync_point);
+
+  // The RenderFrameHost that routes messages to the parent frame's renderer
+  // process.
+  // TODO(kenrb): The type becomes RenderFrameProxyHost when that class comes
+  // to exist.
+  RenderFrameHostImpl* frame_proxy_in_parent_renderer_;

[Charlie Reis, 2013/12/17 01:09:31]

This name is much clearer.

[awong, 2013/12/17 02:45:27]

yay.

+
+  // The RenderWidgetHostView for the child frame. Initially NULL.
+  RenderWidgetHostViewChildFrame* child_frame_view_;
+
+  gfx::Rect child_frame_rect_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
+