Revert of [GRC] Process Coordination Unit support for Global Resource Controller

services/resource_coordinator/coordination_unit/coordination_unit_impl.cc

 // Copyright 2017 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 "services/resource_coordinator/coordination_unit/coordination_unit_impl.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/logging.h"
@@ skipping 199 matching lines @@
   policy_callback_ = std::move(callback);
 
   RecalcCoordinationPolicy();
 }
 
 void CoordinationUnitImpl::UnregisterCoordinationPolicyCallback() {
   policy_callback_.reset();
   current_policy_.reset();
 }
 
-double CoordinationUnitImpl::GetCPUUsageForTesting() {
-  return -1.0;
-}
-
 }  // namespace resource_coordinator