(not for review) Fix composited-to-non-composited corruption on Linux.

content/gpu/gpu_child_thread.cc

Index: content/gpu/gpu_child_thread.cc
diff --git a/content/gpu/gpu_child_thread.cc b/content/gpu/gpu_child_thread.cc
index 170b3648b564ec78fe9d69f4d5a434a10f43850e..f44b9ddf0556c52ad5d2bd4c5bc37a076c9faf76 100644
--- a/content/gpu/gpu_child_thread.cc
+++ b/content/gpu/gpu_child_thread.cc
@@ -18,6 +18,9 @@
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_sync_message_filter.h"
 #include "ui/gl/gl_implementation.h"
+#if defined(TOOLKIT_GTK)
+#include "ui/gl/gl_surface_glx.h"
+#endif
 
 namespace content {
 namespace {
@@ -105,6 +108,8 @@ bool GpuChildThread::OnControlMessageReceived(const IPC::Message& msg) {
     IPC_MESSAGE_HANDLER(GpuMsg_Crash, OnCrash)
     IPC_MESSAGE_HANDLER(GpuMsg_Hang, OnHang)
     IPC_MESSAGE_HANDLER(GpuMsg_DisableWatchdog, OnDisableWatchdog)
+    IPC_MESSAGE_HANDLER(GpuMsg_AcceleratedCompositingStateChange,
+                        OnAcceleratedCompositingStateChange)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
 
@@ -236,5 +241,13 @@ void GpuChildThread::OnDisableWatchdog() {
   }
 }
 
+#if defined(TOOLKIT_GTK)
+void GpuChildThread::OnAcceleratedCompositingStateChange(
+    int32 surface_id, bool surface_compositing_enabled) {
+  gfx::NativeViewGLSurfaceGLX::AcceleratedCompositingStateChange(
+      surface_id, surface_compositing_enabled);
+}
+#endif
+
 }  // namespace content