Fix unit test style in Source/platform/, part 1.

Source/platform/geometry/FloatSizeTest.cpp

Index: Source/platform/geometry/FloatSizeTest.cpp
diff --git a/Source/platform/geometry/FloatSizeTest.cpp b/Source/platform/geometry/FloatSizeTest.cpp
index 0490f53c723fb5f6fc8de0ca5e2f9605d253614b..56e2deb3c23146bf00b20661bfc1d7b7d6a5d128 100644
--- a/Source/platform/geometry/FloatSizeTest.cpp
+++ b/Source/platform/geometry/FloatSizeTest.cpp
@@ -6,12 +6,9 @@
 #include "platform/geometry/FloatSize.h"
 
 #include "platform/geometry/GeometryTestHelpers.h"
-
 #include <gtest/gtest.h>
 
-using namespace blink;
-
-namespace {
+namespace blink {
 
 TEST(FloatSizeTest, DiagonalLengthTest)
 {
@@ -30,4 +27,4 @@ TEST(FloatSizeTest, DiagonalLengthTest)
     EXPECT_PRED_FORMAT2(GeometryTest::AssertAlmostEqual, s4.diagonalLength(), .707106781186548e20f);
 }
 
-}
+} // namespace blink