Fix base::internal::WeakReferenceOwner races.

base/memory/weak_ptr.cc

 // Copyright (c) 2011 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 "base/memory/weak_ptr.h"
 
 namespace base {
 namespace internal {
 
 WeakReference::Flag::Flag(Flag** handle) : handle_(handle) {
@@ skipping 28 matching lines @@
 }
 
 WeakReferenceOwner::WeakReferenceOwner() : flag_(NULL) {
 }
 
 WeakReferenceOwner::~WeakReferenceOwner() {
   Invalidate();
 }
 
 WeakReference WeakReferenceOwner::GetRef() const {
+  AutoLock auto_lock(lock_);
   if (!flag_)
     flag_ = new WeakReference::Flag(&flag_);
   return WeakReference(flag_);
 }
 
 void WeakReferenceOwner::Invalidate() {
   if (flag_) {
     flag_->Invalidate();
     flag_ = NULL;
   }
 }
 
 WeakPtrBase::WeakPtrBase() {
 }
 
 WeakPtrBase::~WeakPtrBase() {
 }
 
 WeakPtrBase::WeakPtrBase(const WeakReference& ref) : ref_(ref) {
 }
 
 }  // namespace internal
 }  // namespace base