Standardize usage of virtual/override/final specifiers.

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 fe353c3f1670c7b5e06421ee68c484ae961777f6..59ea63e0b3fa380291935d555490b920750ce422 100644
--- a/gpu/command_buffer/service/gpu_tracer_unittest.cc
+++ b/gpu/command_buffer/service/gpu_tracer_unittest.cc
@@ -163,12 +163,12 @@ class BaseGpuTracerTest : public GpuServiceTest {
   }
 
  protected:
-  virtual void SetUp() {
+  void SetUp() override {
     GpuServiceTest::SetUp();
     gl_fake_queries_.Reset();
   }
 
-  virtual void TearDown() {
+  void TearDown() override {
     gl_.reset();
     gl_fake_queries_.Reset();
     GpuServiceTest::TearDown();