Send a message through the ozone channel to recreate buffers

ui/ozone/platform/drm/gpu/drm_gpu_platform_support.cc

Index: ui/ozone/platform/drm/gpu/drm_gpu_platform_support.cc
diff --git a/ui/ozone/platform/drm/gpu/drm_gpu_platform_support.cc b/ui/ozone/platform/drm/gpu/drm_gpu_platform_support.cc
index 495307f85e4abcbfcbdd338b19c611adc4ca582f..ea41caa411ee9643ca80227114b61c9527c72ae3 100644
--- a/ui/ozone/platform/drm/gpu/drm_gpu_platform_support.cc
+++ b/ui/ozone/platform/drm/gpu/drm_gpu_platform_support.cc
@@ -224,6 +224,11 @@ bool DrmGpuPlatformSupport::OnMessageReceived(const IPC::Message& message) {
   return false;
 }
 
+void DrmGpuPlatformSupport::WindowMappingChanged(
+    gfx::AcceleratedWidget widget) {
+  sender_->Send(new OzoneHostMsg_WindowMappingChanged(widget));
+}
+
 void DrmGpuPlatformSupport::OnCreateWindowDelegate(
     gfx::AcceleratedWidget widget) {
   scoped_ptr<DrmWindow> delegate(