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

third_party/WebKit/Source/core/layout/LayoutTestHelper.h

 // 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.
 
 #ifndef LayoutTestHelper_h
 #define LayoutTestHelper_h
 
 #include <gtest/gtest.h>
 #include <memory>
 
@@ skipping 48 matching lines @@
   // FrameClient overrides:
   void Detached(FrameDetachType) override;
   LocalFrame* Parent() const override { return parent_.Get(); }
 
  private:
   explicit LocalFrameClientWithParent(LocalFrame* parent) : parent_(parent) {}
 
   Member<LocalFrame> parent_;
 };
 
-class RenderingTest : public testing::Test {
+class RenderingTest : public ::testing::Test {
   USING_FAST_MALLOC(RenderingTest);
 
  public:
   virtual FrameSettingOverrideFunction SettingOverrider() const {
     return nullptr;
   }
   virtual ChromeClient& GetChromeClient() const;
 
   RenderingTest(LocalFrameClient* = nullptr);
 
@@ skipping 37 matching lines @@
   void LoadAhem();
 
  private:
   Persistent<LocalFrameClient> local_frame_client_;
   std::unique_ptr<DummyPageHolder> page_holder_;
 };
 
 }  // namespace blink
 
 #endif  // LayoutTestHelper_h