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

third_party/WebKit/Source/platform/scheduler/renderer/idle_time_estimator_unittest.cc

 // 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 "platform/scheduler/renderer/idle_time_estimator.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
 #include "platform/scheduler/base/task_queue_manager.h"
@@ skipping 12 matching lines @@
       const scoped_refptr<TaskQueue>& compositor_task_runner,
       TestTimeSource* test_time_source,
       int sample_count,
       double estimation_percentile)
       : IdleTimeEstimator(compositor_task_runner,
                           test_time_source,
                           sample_count,
                           estimation_percentile) {}
 };
 
-class IdleTimeEstimatorTest : public testing::Test {
+class IdleTimeEstimatorTest : public ::testing::Test {
  public:
   IdleTimeEstimatorTest()
       : frame_length_(base::TimeDelta::FromMilliseconds(16)) {}
 
   ~IdleTimeEstimatorTest() override {}
 
   void SetUp() override {
     clock_.reset(new base::SimpleTestTickClock());
     clock_->Advance(base::TimeDelta::FromMicroseconds(5000));
     test_time_source_.reset(new TestTimeSource(clock_.get()));
@@ skipping 115 matching lines @@
   SimulateFrameWithTwoCompositorTasks(4, 4);
   estimator_->DidCommitFrameToCompositor();
   estimator_->DidProcessTask(task);
 
   EXPECT_EQ(base::TimeDelta::FromMilliseconds(11),
             estimator_->GetExpectedIdleDuration(frame_length_));
 }
 
 }  // namespace scheduler
 }  // namespace blink