Make `chrome` target build without unused data members on Linux.

components/gcm_driver/instance_id/instance_id_impl.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 "components/gcm_driver/instance_id/instance_id_impl.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include "base/base64.h"
@@ skipping 38 matching lines @@
 // static
 scoped_ptr<InstanceID> InstanceID::Create(const std::string& app_id,
                                           gcm::GCMDriver* gcm_driver) {
   return make_scoped_ptr(new InstanceIDImpl(app_id, gcm_driver));
 }
 
 InstanceIDImpl::InstanceIDImpl(const std::string& app_id,
                                gcm::GCMDriver* gcm_driver)
     : InstanceID(app_id),
       gcm_driver_(gcm_driver),
-      load_from_store_(false),
       weak_ptr_factory_(this) {
   GetInstanceIDHandler()->GetInstanceIDData(
       app_id,
       base::Bind(&InstanceIDImpl::GetInstanceIDDataCompleted,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 InstanceIDImpl::~InstanceIDImpl() {
 }
 
@@ skipping 212 matching lines @@
   creation_time_ = base::Time::Now();
 
   // Save to the persistent store.
   GetInstanceIDHandler()->AddInstanceIDData(
       app_id(),
       id_,
       base::Int64ToString(creation_time_.ToInternalValue()));
 }
 
 }  // namespace instance_id