Fix unit test style in core/{dom,editing,html}/.

Source/core/html/canvas/CanvasRenderingContext2DAPITest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
-
 #include "core/html/canvas/CanvasRenderingContext2D.h"
 
 #include "core/frame/FrameView.h"
 #include "core/html/HTMLDocument.h"
 #include "core/html/ImageData.h"
 #include "core/html/canvas/CanvasGradient.h"
 #include "core/html/canvas/CanvasPattern.h"
 #include "core/html/canvas/WebGLRenderingContext.h"
 #include "core/loader/EmptyClients.h"
 #include "core/testing/DummyPageHolder.h"
 #include "platform/graphics/UnacceleratedImageBufferSurface.h"
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
-using namespace blink;
 using ::testing::Mock;
 
-namespace {
+namespace blink {
 
 class CanvasRenderingContext2DAPITest : public ::testing::Test {
 protected:
     CanvasRenderingContext2DAPITest();
-    virtual void SetUp() override;
+    void SetUp() override;
 
     DummyPageHolder& page() const { return *m_dummyPageHolder; }
     HTMLDocument& document() const { return *m_document; }
     HTMLCanvasElement& canvasElement() const { return *m_canvasElement; }
     CanvasRenderingContext2D* context2d() const;
 
     void createContext(OpacityMode);
 
 private:
     OwnPtr<DummyPageHolder> m_dummyPageHolder;
@@ skipping 172 matching lines @@
     EXPECT_FALSE(exceptionState.hadException());
     ImageData* imgdata4 = context2d()->createImageData(-10, -20, exceptionState);
     EXPECT_FALSE(exceptionState.hadException());
 
     EXPECT_EQ((unsigned)800, imgdata1->data()->length());
     EXPECT_EQ((unsigned)800, imgdata2->data()->length());
     EXPECT_EQ((unsigned)800, imgdata3->data()->length());
     EXPECT_EQ((unsigned)800, imgdata4->data()->length());
 }
 
-} // unnamed namespace
+} // namespace blink