Update Linux to use scoped_refptr<T>::get() rather than implicit "operator T*"

gpu/command_buffer/service/renderbuffer_manager.cc

Index: gpu/command_buffer/service/renderbuffer_manager.cc
diff --git a/gpu/command_buffer/service/renderbuffer_manager.cc b/gpu/command_buffer/service/renderbuffer_manager.cc
index a2b766d5de705aee36dfaf089b220c6a90fe97a8..0190c4494523862f50c10f64a70db8fd7523d37e 100644
--- a/gpu/command_buffer/service/renderbuffer_manager.cc
+++ b/gpu/command_buffer/service/renderbuffer_manager.cc
@@ -137,7 +137,7 @@ void RenderbufferManager::CreateRenderbuffer(
 Renderbuffer* RenderbufferManager::GetRenderbuffer(
     GLuint client_id) {
   RenderbufferMap::iterator it = renderbuffers_.find(client_id);
-  return it != renderbuffers_.end() ? it->second : NULL;
+  return it != renderbuffers_.end() ? it->second.get() : NULL;
 }
 
 void RenderbufferManager::RemoveRenderbuffer(GLuint client_id) {