Refactored GLContext to own GPUTiming which spawn GPUTimingClients.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 6b254e0966bb8ad2de4ee746bf53e6f7cb3dc269..4a266d4ef24a88e37bf24554495bc1bb847393f4 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -2445,7 +2445,6 @@ bool GLES2DecoderImpl::Initialize(
   surfaceless_ = surface->IsSurfaceless() && !offscreen;
 
   set_initialized();
-  gpu_tracer_.reset(new GPUTracer(this));
   gpu_state_tracer_ = GPUStateTracer::Create(&state_);
 
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
@@ -2476,6 +2475,9 @@ bool GLES2DecoderImpl::Initialize(
   if (!attrib_parser.Parse(attribs))
     return false;
 
+  // Create GPU Tracer for timing values.
+  gpu_tracer_.reset(new GPUTracer(this));
+
   // Save the loseContextWhenOutOfMemory context creation attribute.
   lose_context_when_out_of_memory_ =
       attrib_parser.lose_context_when_out_of_memory;