Update {virtual,override} to follow C++11 style in ppapi.

ppapi/shared_impl/ppb_device_ref_shared.h

Index: ppapi/shared_impl/ppb_device_ref_shared.h
diff --git a/ppapi/shared_impl/ppb_device_ref_shared.h b/ppapi/shared_impl/ppb_device_ref_shared.h
index e9bccab58b0992a1ce883e1e1d0180f25bcf923f..aac1206d659fabd7cee0a30fec91060526ad4065 100644
--- a/ppapi/shared_impl/ppb_device_ref_shared.h
+++ b/ppapi/shared_impl/ppb_device_ref_shared.h
@@ -38,12 +38,12 @@ class PPAPI_SHARED_EXPORT PPB_DeviceRef_Shared
                        const DeviceRefData& data);
 
   // Resource overrides.
-  virtual PPB_DeviceRef_API* AsPPB_DeviceRef_API() override;
+  PPB_DeviceRef_API* AsPPB_DeviceRef_API() override;
 
   // PPB_DeviceRef_API implementation.
-  virtual const DeviceRefData& GetDeviceRefData() const override;
-  virtual PP_DeviceType_Dev GetType() override;
-  virtual PP_Var GetName() override;
+  const DeviceRefData& GetDeviceRefData() const override;
+  PP_DeviceType_Dev GetType() override;
+  PP_Var GetName() override;
 
  private:
   DeviceRefData data_;