Make base::WeakPtr moveable.

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() : is_valid_(true) {
@@ skipping 16 matching lines @@
       << "WeakPtrs must be checked on the same sequenced thread.";
   return is_valid_;
 }
 
 WeakReference::Flag::~Flag() {
 }
 
 WeakReference::WeakReference() {
 }
 
-WeakReference::WeakReference(const WeakReference& other) = default;
-
 WeakReference::WeakReference(const Flag* flag) : flag_(flag) {
 }
 
 WeakReference::~WeakReference() {
 }
 
+WeakReference::WeakReference(WeakReference&& other) = default;
+
+WeakReference::WeakReference(const WeakReference& other) = default;
+
 bool WeakReference::is_valid() const { return flag_.get() && flag_->IsValid(); }
 
 WeakReferenceOwner::WeakReferenceOwner() {
 }
 
 WeakReferenceOwner::~WeakReferenceOwner() {
   Invalidate();
 }
 
 WeakReference WeakReferenceOwner::GetRef() const {
@@ skipping 15 matching lines @@
 }
 
 WeakPtrBase::~WeakPtrBase() {
 }
 
 WeakPtrBase::WeakPtrBase(const WeakReference& ref) : ref_(ref) {
 }
 
 }  // namespace internal
 }  // namespace base