cc: Unify namespaces for all test files

cc/delay_based_time_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 "cc/delay_based_time_source.h"
 
 #include "cc/test/scheduler_test_common.h"
 #include "cc/thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-using namespace WebKitTests;
-
 namespace cc {
 namespace {
 
 base::TimeDelta interval()
 {
     return base::TimeDelta::FromMicroseconds(base::Time::kMicrosecondsPerSecond / 60);
 }
 
 TEST(DelayBasedTimeSourceTest, TaskPostedAndTickCalled)
 {
@@ skipping 344 matching lines @@
 
     // Start the timer again, but before the next tick time the timer previously
     // planned on using. That same tick time should still be targeted.
     timer->setNow(timer->now() + base::TimeDelta::FromMilliseconds(20));
     timer->setActive(true);
     EXPECT_EQ(13, thread.pendingDelayMs());
 }
 
 }  // namespace
 }  // namespace cc