Fix unit test style in core/{animation,css,fetch,frame,layout,style,timing}/.

Source/core/animation/AnimationClockTest.cpp

Index: Source/core/animation/AnimationClockTest.cpp
diff --git a/Source/core/animation/AnimationClockTest.cpp b/Source/core/animation/AnimationClockTest.cpp
index 6711971d614b1a236c6f33ed2468c91215885376..f28a927b0e5750819a417d0509f0de80c30d6f51 100644
--- a/Source/core/animation/AnimationClockTest.cpp
+++ b/Source/core/animation/AnimationClockTest.cpp
@@ -34,17 +34,16 @@
 #include "wtf/OwnPtr.h"
 #include <gtest/gtest.h>
 
-using namespace blink;
-
-namespace {
+namespace blink {
 
 class AnimationAnimationClockTest : public ::testing::Test {
 public:
     AnimationAnimationClockTest()
         : animationClock(mockTimeFunction)
     { }
+
 protected:
-    virtual void SetUp()
+    void SetUp() override
     {
         mockTime = 0;
         animationClock.resetTimeForTesting();
@@ -140,4 +139,4 @@ TEST_F(AnimationAnimationClockTest, CurrentTimeUpdatesTask)
     EXPECT_EQ(100, animationClock.currentTime());
 }
 
-}
+} // namespace blink