gpu: Fix crash in gpu tracer

gpu/command_buffer/service/gpu_tracer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/gpu_tracer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <deque>
@@ skipping 253 matching lines @@
 bool GPUTracer::Begin(const std::string& category, const std::string& name,
                       GpuTracerSource source) {
   if (!gpu_executing_)
     return false;
 
   DCHECK(source >= 0 && source < NUM_TRACER_SOURCES);
 
   // Push new marker from given 'source'
   markers_[source].push_back(TraceMarker(category, name));
 
+  if (!outputter_) {
+    outputter_ = CreateOutputter(gpu_timing_client_->GetTimerTypeName());
+  }
+
   // Create trace
   if (IsTracing()) {
     began_device_traces_ |= (*gpu_trace_dev_category != 0);
     scoped_refptr<GPUTrace> trace = new GPUTrace(
         outputter_, gpu_timing_client_.get(), source, category, name,
         *gpu_trace_srv_category != 0,
         *gpu_trace_dev_category != 0);
     trace->Start();
     markers_[source].back().trace_ = trace;
   }
@@ skipping 128 matching lines @@
   }
 
   while (!finished_traces_.empty()) {
     finished_traces_.front()->Destroy(have_context);
     finished_traces_.pop_front();
   }
 }
 
 }  // namespace gles2
 }  // namespace gpu