Do V8 GC ASAP if system memory is pressured

components/history/core/browser/history_backend.cc

 // Copyright (c) 2012 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/history/core/browser/history_backend.h"
 
 #include <algorithm>
 #include <functional>
 #include <list>
 #include <map>
@@ skipping 231 matching lines @@
     const HistoryDatabaseParams& history_database_params) {
   // HistoryBackend is created on the UI thread by HistoryService, then the
   // HistoryBackend::Init() method is called on the DB thread. Create the
   // base::SupportsUserData on the DB thread since it is not thread-safe.
   supports_user_data_helper_.reset(new HistoryBackendHelper);
 
   if (!force_fail)
     InitImpl(history_database_params);
   delegate_->DBLoaded();
   typed_url_syncable_service_.reset(new TypedUrlSyncableService(this));
-  memory_pressure_listener_.reset(new base::MemoryPressureListener(
+  memory_pressure_listener_.reset(base::MemoryPressureListener::Create(
       base::Bind(&HistoryBackend::OnMemoryPressure, base::Unretained(this))));
 }
 
 void HistoryBackend::SetOnBackendDestroyTask(base::MessageLoop* message_loop,
                                              const base::Closure& task) {
   if (!backend_destroy_task_.is_null())
     DLOG(WARNING) << "Setting more than one destroy task, overriding";
   backend_destroy_message_loop_ = message_loop;
   backend_destroy_task_ = task;
 }
@@ skipping 2359 matching lines @@
   // transaction is currently open.
   db_->CommitTransaction();
   db_->Vacuum();
   db_->BeginTransaction();
   db_->GetStartDate(&first_recorded_time_);
 
   return true;
 }
 
 }  // namespace history