Use inner HWND for accelerated rendering on windows

chrome/common/gpu_messages_internal.h

 // Copyright (c) 2010 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.
 
 // This header is meant to be included in multiple passes, hence no traditional
 // header guard. It is included by backing_store_messages_internal.h
 // See ipc_message_macros.h for explanation of the macros and passes.
 
 // This file needs to be included again, even though we're actually included
 // from it via utility_messages.h.
@@ skipping 80 matching lines @@
                        GpuHostMsg_AcceleratedSurfaceSetIOSurface_Params)
 
   // This message notifies the browser process that the renderer
   // swapped the buffers associated with the given "window", which
   // should cause the browser to redraw the compositor's contents.
   IPC_MESSAGE_CONTROL4(GpuHostMsg_AcceleratedSurfaceBuffersSwapped,
                        int32, /* renderer_id */
                        int32, /* render_view_id */
                        gfx::PluginWindowHandle /* window */,
                        uint64 /* surface_id */)
+#elif defined(OS_WIN)
+  // Create and get the HWND for the compositor window
+  IPC_SYNC_MESSAGE_CONTROL2_1(GpuHostMsg_CreateCompositorHostWindow,

[apatrick_chromium, 2010/11/11 22:32:15]

Do these synchronous messages introduce the possibility of a deadlock?

[nduca, 2010/11/11 23:53:33]

I'm not 100% sure... when I was implementing this, I built the following
spreadsheet which shows is the init process during which this sync message
occurs:
https://spreadsheets.google.com/a/google.com/ccc?key=0ApoQxJwHXgm1dDVjV3B5V25...

When we issue the CreateCompositorHostWindow occurs, the renderer is blocked on
a sync ipc to the GPU process CreateViewCommandBuffer.

So, we are safe there. The condition that I worry about is the browser trying to
create another accelerated tab while still initializing this one.

+                              int32, /* renderer_id */
+                              int32, /* render_view_id */
+                              gfx::PluginWindowHandle /* compositor_host_id */)
+
+  IPC_SYNC_MESSAGE_CONTROL2_0(GpuHostMsg_ScheduleComposite,
+                              int32, /* renderer_id */
+                              int32 /* render_view_id */)
 #endif
 
 IPC_END_MESSAGES(GpuHost)
 
 //------------------------------------------------------------------------------
 // GPU Channel Messages
 // These are messages from a renderer process to the GPU process.
 IPC_BEGIN_MESSAGES(GpuChannel)
 
   // Tells the GPU process to create a new command buffer that renders directly
@@ skipping 208 matching lines @@
 
   // GpuVideoDecoder report output format change.
   IPC_MESSAGE_ROUTED1(GpuVideoDecoderHostMsg_MediaFormatChange,
                       GpuVideoDecoderFormatChangeParam)
 
   // GpuVideoDecoder report error.
   IPC_MESSAGE_ROUTED1(GpuVideoDecoderHostMsg_ErrorNotification,
                       GpuVideoDecoderErrorInfoParam)
 
 IPC_END_MESSAGES(GpuVideoDecoderHost)