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

third_party/WebKit/Source/core/page/PageOverlayTest.cpp

 // Copyright 2015 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 "core/page/PageOverlay.h"
 
 #include <memory>
 #include "core/exported/WebViewBase.h"
 #include "core/frame/FrameTestHelpers.h"
 #include "core/frame/LocalFrameView.h"
 #include "core/frame/WebLocalFrameBase.h"
 #include "platform/graphics/Color.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 #include "platform/graphics/paint/PaintController.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebCanvas.h"
 #include "public/platform/WebThread.h"
 #include "public/web/WebSettings.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkPaint.h"
 
-using testing::_;
-using testing::AtLeast;
-using testing::Property;
+using ::testing::_;
+using ::testing::AtLeast;
+using ::testing::Property;
 
 namespace blink {
 namespace {
 
 static const int kViewportWidth = 800;
 static const int kViewportHeight = 600;
 
 // These unit tests cover both PageOverlay and PageOverlayList.
 
 void EnableAcceleratedCompositing(WebSettings* settings) {
@@ skipping 113 matching lines @@
   Initialize(kAcceleratedCompositing);
   std::unique_ptr<PageOverlay> page_overlay = CreateSolidYellowOverlay();
   page_overlay->Update();
   GetWebView()->UpdateAllLifecyclePhases();
   EXPECT_EQ(LayoutRect(0, 0, kViewportWidth, kViewportHeight),
             page_overlay->VisualRect());
 }
 
 }  // namespace
 }  // namespace blink