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

Source/core/css/invalidation/DescendantInvalidationSetTest.cpp

Index: Source/core/css/invalidation/DescendantInvalidationSetTest.cpp
diff --git a/Source/core/css/invalidation/DescendantInvalidationSetTest.cpp b/Source/core/css/invalidation/DescendantInvalidationSetTest.cpp
index c49328887b1276e18c7d85b99da747dd870f8a9e..36ecda57183a1512d522532d19a086dc89f89b69 100644
--- a/Source/core/css/invalidation/DescendantInvalidationSetTest.cpp
+++ b/Source/core/css/invalidation/DescendantInvalidationSetTest.cpp
@@ -7,9 +7,7 @@
 
 #include <gtest/gtest.h>
 
-using namespace blink;
-
-namespace {
+namespace blink {
 
 // Once we setWholeSubtreeInvalid, we should not keep the HashSets.
 TEST(DescendantInvalidationSetTest, SubtreeInvalid_AddBefore)
@@ -79,4 +77,4 @@ TEST(DescendantInvalidationSetTest, ShowDebug)
 }
 #endif // NDEBUG
 
-} // namespace
+} // namespace blink