Use inner HWND for accelerated rendering on windows

chrome/common/gpu_messages_internal.h

Index: chrome/common/gpu_messages_internal.h
===================================================================
--- chrome/common/gpu_messages_internal.h	(revision 65702)
+++ chrome/common/gpu_messages_internal.h	(working copy)
@@ -98,6 +98,16 @@
                        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)