convert //gpu to std::unique_ptr

gpu/command_buffer/service/gpu_state_tracer.h

Index: gpu/command_buffer/service/gpu_state_tracer.h
diff --git a/gpu/command_buffer/service/gpu_state_tracer.h b/gpu/command_buffer/service/gpu_state_tracer.h
index 1cb7fe92534aee483fe055ab596b03a05d419311..09a873bd517899d4656c09e1eb4b7f467146e442 100644
--- a/gpu/command_buffer/service/gpu_state_tracer.h
+++ b/gpu/command_buffer/service/gpu_state_tracer.h
@@ -5,8 +5,9 @@
 #ifndef GPU_COMMAND_BUFFER_SERVICE_GPU_STATE_TRACER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_GPU_STATE_TRACER_H_
 
+#include <memory>
+
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 
 namespace gfx {
 class Size;
@@ -20,7 +21,7 @@ struct ContextState;
 // Saves GPU state such as framebuffer contents while tracing.
 class GPUStateTracer {
  public:
-  static scoped_ptr<GPUStateTracer> Create(const ContextState* state);
+  static std::unique_ptr<GPUStateTracer> Create(const ContextState* state);
   ~GPUStateTracer();
 
   // Take a state snapshot with a screenshot of the currently bound framebuffer.