Standardize usage of virtual/override/final specifiers.

gpu/command_buffer/tests/gl_readback_unittest.cc

Index: gpu/command_buffer/tests/gl_readback_unittest.cc
diff --git a/gpu/command_buffer/tests/gl_readback_unittest.cc b/gpu/command_buffer/tests/gl_readback_unittest.cc
index e67cbdc026d250c8746c08f9ff4c47479619487f..cbda25ccfa8ba204d340cfdaae43a260f8e7c3d0 100644
--- a/gpu/command_buffer/tests/gl_readback_unittest.cc
+++ b/gpu/command_buffer/tests/gl_readback_unittest.cc
@@ -21,13 +21,9 @@ namespace gpu {
 
 class GLReadbackTest : public testing::Test {
  protected:
-  virtual void SetUp() {
-    gl_.Initialize(GLManager::Options());
-  }
+  void SetUp() override { gl_.Initialize(GLManager::Options()); }
 
-  virtual void TearDown() {
-    gl_.Destroy();
-  }
+  void TearDown() override { gl_.Destroy(); }
 
   static void WaitForQueryCallback(int q, base::Closure cb) {
     unsigned int done = 0;