Be explicit about namespace testing to not mix it with blink::testing

third_party/WebKit/Source/platform/scroll/ScrollbarThemeAuraTest.cpp

 // Copyright 2016 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 "platform/scroll/ScrollbarThemeAura.h"
 
 #include "platform/scroll/ScrollbarTestSuite.h"
 #include "platform/testing/TestingPlatformSupport.h"
 
 namespace blink {
 
-using testing::Return;
+using ::testing::Return;
 
 namespace {
 
 class ScrollbarThemeAuraButtonOverride final : public ScrollbarThemeAura {
  public:
   ScrollbarThemeAuraButtonOverride() : has_scrollbar_buttons_(true) {}
 
   void SetHasScrollbarButtons(bool value) { has_scrollbar_buttons_ = value; }
 
   bool HasScrollbarButtons(ScrollbarOrientation unused) const override {
     return has_scrollbar_buttons_;
   }
 
  private:
   bool has_scrollbar_buttons_;
 };
 
 }  // namespace
 
-using ScrollbarThemeAuraTest = testing::Test;
+using ScrollbarThemeAuraTest = ::testing::Test;
 
 TEST_F(ScrollbarThemeAuraTest, ButtonSizeHorizontal) {
   ScopedTestingPlatformSupport<TestingPlatformSupportWithMockScheduler>
       platform;
 
   MockScrollableArea* mock_scrollable_area = MockScrollableArea::Create();
   ScrollbarThemeMock mock_theme;
   Scrollbar* scrollbar =
       Scrollbar::CreateForTesting(mock_scrollable_area, kHorizontalScrollbar,
                                   kRegularScrollbar, &mock_theme);
@@ skipping 52 matching lines @@
 
   scrollbar->SetFrameRect(IntRect(1, 2, 3, 4));
   IntSize size = theme.ButtonSize(*scrollbar);
   EXPECT_EQ(0, size.Width());
   EXPECT_EQ(0, size.Height());
 
   ThreadState::Current()->CollectAllGarbage();
 }
 
 }  // namespace blink