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

gpu/command_buffer/service/vertex_array_manager.cc

Index: gpu/command_buffer/service/vertex_array_manager.cc
diff --git a/gpu/command_buffer/service/vertex_array_manager.cc b/gpu/command_buffer/service/vertex_array_manager.cc
index 3b94fa72ba8f24983fa2958ee49f6ee85bcf3f44..974751941ce4a41fdbcc5efe596560db1995bed5 100644
--- a/gpu/command_buffer/service/vertex_array_manager.cc
+++ b/gpu/command_buffer/service/vertex_array_manager.cc
@@ -41,7 +41,7 @@ void VertexArrayManager::CreateVertexAttribManager(
 VertexAttribManager* VertexArrayManager::GetVertexAttribManager(
     GLuint client_id) {
   VertexAttribManagerMap::iterator it = vertex_attrib_managers_.find(client_id);
-  return it != vertex_attrib_managers_.end() ? it->second : NULL;
+  return it != vertex_attrib_managers_.end() ? it->second.get() : NULL;
 }
 
 void VertexArrayManager::RemoveVertexAttribManager(GLuint client_id) {