Switch DRM platform to using a separate thread

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

Index: ui/ozone/platform/drm/gpu/drm_vsync_provider.cc
diff --git a/ui/ozone/platform/drm/gpu/drm_vsync_provider.cc b/ui/ozone/platform/drm/gpu/drm_vsync_provider.cc
index a187da5f0d7dfbb561406bc731680264be1ecd0e..4da0cc0d9f464a22980140c46c50eced7bd0d2f0 100644
--- a/ui/ozone/platform/drm/gpu/drm_vsync_provider.cc
+++ b/ui/ozone/platform/drm/gpu/drm_vsync_provider.cc
@@ -5,17 +5,22 @@
 #include "ui/ozone/platform/drm/gpu/drm_vsync_provider.h"
 
 #include "ui/ozone/platform/drm/gpu/drm_window.h"
+#include "ui/ozone/platform/drm/gpu/proxy_helpers.h"
 
 namespace ui {
 
-DrmVSyncProvider::DrmVSyncProvider(DrmWindow* window) : window_(window) {
-}
+DrmVSyncProvider::DrmVSyncProvider(
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+    base::WeakPtr<DrmWindow> window)
+    : task_runner_(task_runner), window_(window) {}
 
 DrmVSyncProvider::~DrmVSyncProvider() {
 }
 
 void DrmVSyncProvider::GetVSyncParameters(const UpdateVSyncCallback& callback) {
-  window_->GetVSyncParameters(callback);
+  task_runner_->PostTask(FROM_HERE,
+                         base::Bind(&DrmWindow::GetVSyncParameters, window_,
+                                    CreateSafeCallback(callback)));
 }
 
 }  // namespace ui