base: Add free list implementation to browser-wide discardable memory system.

content/common/host_discardable_shared_memory_manager.cc

 // 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.
 
 #include "content/common/host_discardable_shared_memory_manager.h"
 
 #include <algorithm>
 
 #include "base/callback.h"
 #include "base/debug/crash_logging.h"
@@ skipping 34 matching lines @@
 }
 
 HostDiscardableSharedMemoryManager::~HostDiscardableSharedMemoryManager() {
 }
 
 HostDiscardableSharedMemoryManager*
 HostDiscardableSharedMemoryManager::current() {
   return g_discardable_shared_memory_manager.Pointer();
 }
 
-scoped_ptr<base::DiscardableSharedMemory>
-HostDiscardableSharedMemoryManager::AllocateLockedDiscardableSharedMemory(
+scoped_ptr<base::DiscardableMemoryShmemChunk>
+HostDiscardableSharedMemoryManager::AllocateLockedDiscardableMemory(
     size_t size) {
   // TODO(reveman): Need to implement this for discardable memory support in
   // the browser process.
   NOTIMPLEMENTED();
-  return scoped_ptr<base::DiscardableSharedMemory>();
+  return nullptr;
 }
 
 void HostDiscardableSharedMemoryManager::
     AllocateLockedDiscardableSharedMemoryForChild(
         base::ProcessHandle process_handle,
         size_t size,
         base::SharedMemoryHandle* shared_memory_handle) {
   base::AutoLock lock(lock_);
 
   // Memory usage must be reduced to prevent the addition of |size| from
@@ skipping 175 matching lines @@
 
   enforce_memory_policy_pending_ = true;
   base::MessageLoop::current()->PostDelayedTask(
       FROM_HERE,
       base::Bind(&HostDiscardableSharedMemoryManager::EnforceMemoryPolicy,
                  weak_ptr_factory_.GetWeakPtr()),
       base::TimeDelta::FromMilliseconds(kEnforceMemoryPolicyDelayMs));
 }
 
 }  // namespace content