Standardize usage of virtual/override/final in content/

content/child/child_gpu_memory_buffer_manager.h

Index: content/child/child_gpu_memory_buffer_manager.h
diff --git a/content/child/child_gpu_memory_buffer_manager.h b/content/child/child_gpu_memory_buffer_manager.h
index 981e70e9a875850add267c289403bc3960a0acb0..74b078f7e48ab71061ae42b974b67e11e500a9d7 100644
--- a/content/child/child_gpu_memory_buffer_manager.h
+++ b/content/child/child_gpu_memory_buffer_manager.h
@@ -13,14 +13,14 @@ namespace content {
 class ChildGpuMemoryBufferManager : public cc::GpuMemoryBufferManager {
  public:
   ChildGpuMemoryBufferManager(ThreadSafeSender* sender);
-  virtual ~ChildGpuMemoryBufferManager();
+  ~ChildGpuMemoryBufferManager() override;
 
   // Overridden from cc::GpuMemoryBufferManager:
-  virtual scoped_ptr<gfx::GpuMemoryBuffer> AllocateGpuMemoryBuffer(
+  scoped_ptr<gfx::GpuMemoryBuffer> AllocateGpuMemoryBuffer(
       const gfx::Size& size,
       gfx::GpuMemoryBuffer::Format format,
       gfx::GpuMemoryBuffer::Usage usage) override;
-  virtual gfx::GpuMemoryBuffer* GpuMemoryBufferFromClientBuffer(
+  gfx::GpuMemoryBuffer* GpuMemoryBufferFromClientBuffer(
       ClientBuffer buffer) override;
 
  private: