Standardize usage of virtual/override/final in cc/

cc/resources/video_resource_updater.cc

Index: cc/resources/video_resource_updater.cc
diff --git a/cc/resources/video_resource_updater.cc b/cc/resources/video_resource_updater.cc
index f62b6e62aa14a830a87504ff19e9f0b0d9a3c114..4d0e1256f667699ea204865f02b2c3338f0516db 100644
--- a/cc/resources/video_resource_updater.cc
+++ b/cc/resources/video_resource_updater.cc
@@ -26,11 +26,11 @@ const ResourceFormat kRGBResourceFormat = RGBA_8888;
 class SyncPointClientImpl : public media::VideoFrame::SyncPointClient {
  public:
   explicit SyncPointClientImpl(gpu::gles2::GLES2Interface* gl) : gl_(gl) {}
-  virtual ~SyncPointClientImpl() {}
-  virtual uint32 InsertSyncPoint() override {
+  ~SyncPointClientImpl() override {}
+  uint32 InsertSyncPoint() override {
     return GLC(gl_, gl_->InsertSyncPointCHROMIUM());
   }
-  virtual void WaitSyncPoint(uint32 sync_point) override {
+  void WaitSyncPoint(uint32 sync_point) override {
     GLC(gl_, gl_->WaitSyncPointCHROMIUM(sync_point));
   }