Remove implicit conversions from scoped_refptr to T* in gpu/

gpu/command_buffer/service/common_decoder.cc

Index: gpu/command_buffer/service/common_decoder.cc
diff --git a/gpu/command_buffer/service/common_decoder.cc b/gpu/command_buffer/service/common_decoder.cc
index 06cf3a4bb37d9876a9e2dbbe0622002f4f4e3f81..86a37ba77e5fb8dd94c4c285ed0ce3351c46ac92 100644
--- a/gpu/command_buffer/service/common_decoder.cc
+++ b/gpu/command_buffer/service/common_decoder.cc
@@ -65,7 +65,7 @@ void* CommonDecoder::GetAddressAndCheckSize(unsigned int shm_id,
                                             unsigned int data_size) {
   CHECK(engine_);
   scoped_refptr<gpu::Buffer> buffer = engine_->GetSharedMemoryBuffer(shm_id);
-  if (!buffer)
+  if (!buffer.get())
     return NULL;
   return buffer->GetDataAddress(data_offset, data_size);
 }