Cleanup: IWYU for base/gtest_prod_util.h.

cc/scheduler/begin_frame_source_unittest.cc

 // Copyright 2011 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 <deque>
 #include <string>
 
 #include "base/basictypes.h"
-#include "base/gtest_prod_util.h"
 #include "base/test/test_simple_task_runner.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/test/begin_frame_args_test.h"
 #include "cc/test/scheduler_test_common.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 // Macros to help set up expected calls on the MockBeginFrameObserver.
 #define EXPECT_BEGIN_FRAME_DROP(obs, frame_time, deadline, interval)       \
   {                                                                        \
@@ skipping 750 matching lines @@
   mux_->SetActiveSource(source2_);
   SEND_BEGIN_FRAME_DROP(*source2_, 750, 1050, 300);
   SEND_BEGIN_FRAME_USED(*source2_, 1050, 1250, 300);
 
   mux_->SetActiveSource(source1_);
   SEND_BEGIN_FRAME_DROP(*source2_, 1100, 1400, 300);
 }
 
 }  // namespace
 }  // namespace cc