Standardize usage of virtual/override/final in cc/

cc/test/test_gpu_memory_buffer_manager.cc

Index: cc/test/test_gpu_memory_buffer_manager.cc
diff --git a/cc/test/test_gpu_memory_buffer_manager.cc b/cc/test/test_gpu_memory_buffer_manager.cc
index 855959e8d08a6a43b032669e067ba2eaf7f703dc..1f34988047cbe3a28e131cfade84d7f8eca9ed2e 100644
--- a/cc/test/test_gpu_memory_buffer_manager.cc
+++ b/cc/test/test_gpu_memory_buffer_manager.cc
@@ -19,25 +19,25 @@ class GpuMemoryBufferImpl : public gfx::GpuMemoryBuffer {
         mapped_(false) {}
 
   // Overridden from gfx::GpuMemoryBuffer:
-  virtual void* Map() override {
+  void* Map() override {
     DCHECK(!mapped_);
     mapped_ = true;
     return pixels_.get();
   }
-  virtual void Unmap() override {
+  void Unmap() override {
     DCHECK(mapped_);
     mapped_ = false;
   }
-  virtual bool IsMapped() const override { return mapped_; }
-  virtual Format GetFormat() const override { return format_; }
-  virtual uint32 GetStride() const override {
+  bool IsMapped() const override { return mapped_; }
+  Format GetFormat() const override { return format_; }
+  uint32 GetStride() const override {
     return size_.width() * BytesPerPixel(format_);
   }
-  virtual gfx::GpuMemoryBufferHandle GetHandle() const override {
+  gfx::GpuMemoryBufferHandle GetHandle() const override {
     NOTREACHED();
     return gfx::GpuMemoryBufferHandle();
   }
-  virtual ClientBuffer AsClientBuffer() override {
+  ClientBuffer AsClientBuffer() override {
     return reinterpret_cast<ClientBuffer>(this);
   }