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

gpu/command_buffer/service/gpu_tracer.cc

Index: gpu/command_buffer/service/gpu_tracer.cc
diff --git a/gpu/command_buffer/service/gpu_tracer.cc b/gpu/command_buffer/service/gpu_tracer.cc
index 85814997769274d67201f530fcc6ac6dca046fa5..76485c6219a54d5485d648110564deabb24aa3c8 100644
--- a/gpu/command_buffer/service/gpu_tracer.cc
+++ b/gpu/command_buffer/service/gpu_tracer.cc
@@ -237,7 +237,7 @@ void GLARBTimerTrace::Process() {
 
 bool GPUTracerImpl::Begin(const std::string& name) {
   // Make sure we are not nesting trace commands.
-  if (current_trace_)
+  if (current_trace_.get())
     return false;
 
   current_trace_ = CreateTrace(name);
@@ -246,7 +246,7 @@ bool GPUTracerImpl::Begin(const std::string& name) {
 }
 
 bool GPUTracerImpl::End() {
-  if (!current_trace_)
+  if (!current_trace_.get())
     return false;
 
   current_trace_->End();
@@ -270,7 +270,7 @@ void GPUTracerImpl::Process() {
 }
 
 const std::string& GPUTracerImpl::CurrentName() const {
-  if (!current_trace_)
+  if (!current_trace_.get())
     return EmptyString();
   return current_trace_->name();
 }