Standardize usage of virtual/override/final in cc/

cc/resources/gpu_raster_worker_pool.cc

Index: cc/resources/gpu_raster_worker_pool.cc
diff --git a/cc/resources/gpu_raster_worker_pool.cc b/cc/resources/gpu_raster_worker_pool.cc
index 2d1e888a6388f67fd48aff1548ae4cbe6e4f5873..a0bc86fd10bc89c0e34c6868aa3ef28dfdd1340c 100644
--- a/cc/resources/gpu_raster_worker_pool.cc
+++ b/cc/resources/gpu_raster_worker_pool.cc
@@ -32,10 +32,10 @@ class RasterBufferImpl : public RasterBuffer {
         multi_picture_draw_(multi_picture_draw) {}
 
   // Overridden from RasterBuffer:
-  virtual void Playback(const PicturePileImpl* picture_pile,
-                        const gfx::Rect& rect,
-                        float scale,
-                        RenderingStatsInstrumentation* stats) override {
+  void Playback(const PicturePileImpl* picture_pile,
+                const gfx::Rect& rect,
+                float scale,
+                RenderingStatsInstrumentation* stats) override {
     if (!lock_.sk_surface())
       return;