Update from chromium https://crrev.com/301725/

gpu/command_buffer/client/buffer_tracker_unittest.cc

Index: gpu/command_buffer/client/buffer_tracker_unittest.cc
diff --git a/gpu/command_buffer/client/buffer_tracker_unittest.cc b/gpu/command_buffer/client/buffer_tracker_unittest.cc
index a24400984beb3cfc242276a3aaeee61992132fde..a92839613407075a6d7498f88eb50145cd628c84 100644
--- a/gpu/command_buffer/client/buffer_tracker_unittest.cc
+++ b/gpu/command_buffer/client/buffer_tracker_unittest.cc
@@ -53,7 +53,7 @@ class BufferTrackerTest : public testing::Test {
   static const int32 kCommandBufferSizeBytes =
       kNumCommandEntries * sizeof(CommandBufferEntry);
 
-  virtual void SetUp() {
+  void SetUp() override {
     command_buffer_.reset(new MockClientCommandBufferImpl());
     helper_.reset(new GLES2CmdHelper(command_buffer_.get()));
     helper_->Initialize(kCommandBufferSizeBytes);
@@ -62,7 +62,7 @@ class BufferTrackerTest : public testing::Test {
     buffer_tracker_.reset(new BufferTracker(mapped_memory_.get()));
   }
 
-  virtual void TearDown() {
+  void TearDown() override {
     buffer_tracker_.reset();
     mapped_memory_.reset();
     helper_.reset();