Added support for GPU Tracing on mobile devices which support it.

gpu/command_buffer/service/gpu_tracer_unittest.cc

Index: gpu/command_buffer/service/gpu_tracer_unittest.cc
diff --git a/gpu/command_buffer/service/gpu_tracer_unittest.cc b/gpu/command_buffer/service/gpu_tracer_unittest.cc
index 75d66e595475a3ec0ebad26a6a7477b49813628d..8da9ad08f0db8b487a97f7df33fcb92326f14cf9 100644
--- a/gpu/command_buffer/service/gpu_tracer_unittest.cc
+++ b/gpu/command_buffer/service/gpu_tracer_unittest.cc
@@ -180,7 +180,8 @@ TEST_F(GpuTracerTest, GPUTrace) {
                 Trace(trace_name, expect_start_time, expect_end_time));
 
     scoped_refptr<GPUTrace> trace =
-        new GPUTrace(outputter_ref, trace_name, offset_time);
+        new GPUTrace(outputter_ref, trace_name, offset_time,
+                     kTracerTypeARBTimer);
 
     gl_fake_queries_.SetCurrentGLTime(start_timestamp);
     trace->Start();