convert //gpu to std::unique_ptr

gpu/blink/webgraphicscontext3d_impl.h

Index: gpu/blink/webgraphicscontext3d_impl.h
diff --git a/gpu/blink/webgraphicscontext3d_impl.h b/gpu/blink/webgraphicscontext3d_impl.h
index 0dc5bc58bf3715c346dfbbdacc5aaff977e3537a..6088b9758c619694c33886e4c2107c2d3148a7aa 100644
--- a/gpu/blink/webgraphicscontext3d_impl.h
+++ b/gpu/blink/webgraphicscontext3d_impl.h
@@ -7,11 +7,11 @@
 
 #include <stdint.h>
 
+#include <memory>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
-#include "base/memory/scoped_ptr.h"
 #include "gpu/blink/gpu_blink_export.h"
 #include "third_party/WebKit/public/platform/WebGraphicsContext3D.h"
 #include "third_party/WebKit/public/platform/WebString.h"
@@ -65,7 +65,7 @@ class GPU_BLINK_EXPORT WebGraphicsContext3DImpl
 
   WebGraphicsContext3D::WebGraphicsErrorMessageCallback*
       error_message_callback_;
-  scoped_ptr<WebGraphicsContext3DErrorMessageCallback>
+  std::unique_ptr<WebGraphicsContext3DErrorMessageCallback>
       client_error_message_callback_;
 
   ::gpu::gles2::GLES2Interface* gl_;