Revert of Straightens outs DEPS in mojo/common

mojo/message_pump/time_helper.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 MOJO_MESSAGE_PUMP_TIME_HELPER_H_
-#define MOJO_MESSAGE_PUMP_TIME_HELPER_H_
-
-#include "base/time/time.h"
-
-namespace base {
-class TickClock;
-}
-
-namespace mojo {
-namespace common {
-namespace test {
-
-// Sets the TickClock used for getting TimeTicks::Now(). This is currently used
-// by both HandleWatcher and MessagePumpMojo.
-void SetTickClockForTest(base::TickClock* clock);
-
-}  // namespace test
-
-namespace internal {
-
-// Returns now. Used internally; generally not useful.
-base::TimeTicks NowTicks();
-
-}  // namespace internal
-}  // namespace common
-}  // namespace mojo
-
-#endif  // MOJO_MESSAGE_PUMP_TIME_HELPER_H_