Compile issue with unit test found on trybots. Fixing.

R=joedow@chromium.org

Review-Url: https://codereview.chromium.org/2815673002
Cr-Commit-Position: refs/heads/master@{#463651}

remoting/client/ios/key_input_unittest.mm

@@ -60,7 +60,7 @@ - (void)keyboardActionKeyCode:(uint32_t)keyPressed isKeyDown:(BOOL)keyDown {
 
 class KeyInputTest : public ::testing::Test {
  protected:
-  virtual void SetUp() override {
+  void SetUp() override {
     keyInput_ = [[KeyInput allocWithZone:nil] init];
     delegateTester_ = [[KeyInputDelegateTester alloc] init];
     keyInput_.delegate = delegateTester_;