Move some files from base to base/memory.

raw_scoped_refptr_mismatch_checker.h
ref_counted.cc
ref_counted.h
ref_counted_memory.cc
ref_counted_memory.h
ref_counted_unittest.cc
scoped_callback_factory.h
scoped_comptr_win.h
scoped_handle.h
scoped_native_library.cc
scoped_native_library.h
scoped_native_library_unittest.cc
scoped_nsobject.h
scoped_open_process.h
scoped_ptr.h
scoped_ptr_unittest.cc
scoped_temp_dir.cc
scoped_temp_dir.h
scoped_temp_dir_unittest.cc
scoped_vector.h
singleton.h
singleton_objc.h
singleton_unittest.cc
linked_ptr.h
linked_ptr_unittest.cc
weak_ptr.cc
weak_ptr.h
weak_ptr_unittest.cc

BUG=None
TEST=Compile

Review URL: http://codereview.chromium.org/6714032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@79524 0039d316-1c4b-4281-b951-d872f2087c98

29 files changed, 3557 insertions, 0 deletions

diff --git a/base/memory/linked_ptr.h b/base/memory/linked_ptr.h
new file mode 100644
index 0000000..41931d8
--- /dev/null
+++ b/base/memory/linked_ptr.h
@@ -0,0 +1,182 @@
+// 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.
+//
+// A "smart" pointer type with reference tracking.  Every pointer to a
+// particular object is kept on a circular linked list.  When the last pointer
+// to an object is destroyed or reassigned, the object is deleted.
+//
+// Used properly, this deletes the object when the last reference goes away.
+// There are several caveats:
+// - Like all reference counting schemes, cycles lead to leaks.
+// - Each smart pointer is actually two pointers (8 bytes instead of 4).
+// - Every time a pointer is released, the entire list of pointers to that
+//   object is traversed.  This class is therefore NOT SUITABLE when there
+//   will often be more than two or three pointers to a particular object.
+// - References are only tracked as long as linked_ptr<> objects are copied.
+//   If a linked_ptr<> is converted to a raw pointer and back, BAD THINGS
+//   will happen (double deletion).
+//
+// A good use of this class is storing object references in STL containers.
+// You can safely put linked_ptr<> in a vector<>.
+// Other uses may not be as good.
+//
+// Note: If you use an incomplete type with linked_ptr<>, the class
+// *containing* linked_ptr<> must have a constructor and destructor (even
+// if they do nothing!).
+//
+// Thread Safety:
+//   A linked_ptr is NOT thread safe. Copying a linked_ptr object is
+//   effectively a read-write operation.
+//
+// Alternative: to linked_ptr is shared_ptr, which
+//  - is also two pointers in size (8 bytes for 32 bit addresses)
+//  - is thread safe for copying and deletion
+//  - supports weak_ptrs
+
+#ifndef BASE_MEMORY_LINKED_PTR_H_
+#define BASE_MEMORY_LINKED_PTR_H_
+#pragma once
+
+#include "base/logging.h"  // for CHECK macros
+
+// This is used internally by all instances of linked_ptr<>.  It needs to be
+// a non-template class because different types of linked_ptr<> can refer to
+// the same object (linked_ptr<Superclass>(obj) vs linked_ptr<Subclass>(obj)).
+// So, it needs to be possible for different types of linked_ptr to participate
+// in the same circular linked list, so we need a single class type here.
+//
+// DO NOT USE THIS CLASS DIRECTLY YOURSELF.  Use linked_ptr<T>.
+class linked_ptr_internal {
+ public:
+  // Create a new circle that includes only this instance.
+  void join_new() {
+    next_ = this;
+  }
+
+  // Join an existing circle.
+  void join(linked_ptr_internal const* ptr) {
+    next_ = ptr->next_;
+    ptr->next_ = this;
+  }
+
+  // Leave whatever circle we're part of.  Returns true iff we were the
+  // last member of the circle.  Once this is done, you can join() another.
+  bool depart() {
+    if (next_ == this) return true;
+    linked_ptr_internal const* p = next_;
+    while (p->next_ != this) p = p->next_;
+    p->next_ = next_;
+    return false;
+  }
+
+ private:
+  mutable linked_ptr_internal const* next_;
+};
+
+template <typename T>
+class linked_ptr {
+ public:
+  typedef T element_type;
+
+  // Take over ownership of a raw pointer.  This should happen as soon as
+  // possible after the object is created.
+  explicit linked_ptr(T* ptr = NULL) { capture(ptr); }
+  ~linked_ptr() { depart(); }
+
+  // Copy an existing linked_ptr<>, adding ourselves to the list of references.
+  template <typename U> linked_ptr(linked_ptr<U> const& ptr) { copy(&ptr); }
+
+  linked_ptr(linked_ptr const& ptr) {
+    DCHECK_NE(&ptr, this);
+    copy(&ptr);
+  }
+
+  // Assignment releases the old value and acquires the new.
+  template <typename U> linked_ptr& operator=(linked_ptr<U> const& ptr) {
+    depart();
+    copy(&ptr);
+    return *this;
+  }
+
+  linked_ptr& operator=(linked_ptr const& ptr) {
+    if (&ptr != this) {
+      depart();
+      copy(&ptr);
+    }
+    return *this;
+  }
+
+  // Smart pointer members.
+  void reset(T* ptr = NULL) {
+    depart();
+    capture(ptr);
+  }
+  T* get() const { return value_; }
+  T* operator->() const { return value_; }
+  T& operator*() const { return *value_; }
+  // Release ownership of the pointed object and returns it.
+  // Sole ownership by this linked_ptr object is required.
+  T* release() {
+    bool last = link_.depart();
+    CHECK(last);
+    T* v = value_;
+    value_ = NULL;
+    return v;
+  }
+
+  bool operator==(const T* p) const { return value_ == p; }
+  bool operator!=(const T* p) const { return value_ != p; }
+  template <typename U>
+  bool operator==(linked_ptr<U> const& ptr) const {
+    return value_ == ptr.get();
+  }
+  template <typename U>
+  bool operator!=(linked_ptr<U> const& ptr) const {
+    return value_ != ptr.get();
+  }
+
+ private:
+  template <typename U>
+  friend class linked_ptr;
+
+  T* value_;
+  linked_ptr_internal link_;
+
+  void depart() {
+    if (link_.depart()) delete value_;
+  }
+
+  void capture(T* ptr) {
+    value_ = ptr;
+    link_.join_new();
+  }
+
+  template <typename U> void copy(linked_ptr<U> const* ptr) {
+    value_ = ptr->get();
+    if (value_)
+      link_.join(&ptr->link_);
+    else
+      link_.join_new();
+  }
+};
+
+template<typename T> inline
+bool operator==(T* ptr, const linked_ptr<T>& x) {
+  return ptr == x.get();
+}
+
+template<typename T> inline
+bool operator!=(T* ptr, const linked_ptr<T>& x) {
+  return ptr != x.get();
+}
+
+// A function to convert T* into linked_ptr<T>
+// Doing e.g. make_linked_ptr(new FooBarBaz<type>(arg)) is a shorter notation
+// for linked_ptr<FooBarBaz<type> >(new FooBarBaz<type>(arg))
+template <typename T>
+linked_ptr<T> make_linked_ptr(T* ptr) {
+  return linked_ptr<T>(ptr);
+}
+
+#endif  // BASE_MEMORY_LINKED_PTR_H_
diff --git a/base/memory/linked_ptr_unittest.cc b/base/memory/linked_ptr_unittest.cc
new file mode 100644
index 0000000..ae10fc28
--- /dev/null
+++ b/base/memory/linked_ptr_unittest.cc
@@ -0,0 +1,108 @@
+// 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 <string>
+
+#include "base/memory/linked_ptr.h"
+#include "base/stringprintf.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+int num = 0;
+
+std::string history;
+
+// Class which tracks allocation/deallocation
+struct A {
+  A(): mynum(num++) { history += base::StringPrintf("A%d ctor\n", mynum); }
+  virtual ~A() { history += base::StringPrintf("A%d dtor\n", mynum); }
+  virtual void Use() { history += base::StringPrintf("A%d use\n", mynum); }
+  int mynum;
+};
+
+// Subclass
+struct B: public A {
+  B() { history += base::StringPrintf("B%d ctor\n", mynum); }
+  ~B() { history += base::StringPrintf("B%d dtor\n", mynum); }
+  virtual void Use() { history += base::StringPrintf("B%d use\n", mynum); }
+};
+
+}  // namespace
+
+TEST(LinkedPtrTest, Test) {
+  {
+    linked_ptr<A> a0, a1, a2;
+    a0 = a0;
+    a1 = a2;
+    ASSERT_EQ(a0.get(), static_cast<A*>(NULL));
+    ASSERT_EQ(a1.get(), static_cast<A*>(NULL));
+    ASSERT_EQ(a2.get(), static_cast<A*>(NULL));
+    ASSERT_TRUE(a0 == NULL);
+    ASSERT_TRUE(a1 == NULL);
+    ASSERT_TRUE(a2 == NULL);
+
+    {
+      linked_ptr<A> a3(new A);
+      a0 = a3;
+      ASSERT_TRUE(a0 == a3);
+      ASSERT_TRUE(a0 != NULL);
+      ASSERT_TRUE(a0.get() == a3);
+      ASSERT_TRUE(a0 == a3.get());
+      linked_ptr<A> a4(a0);
+      a1 = a4;
+      linked_ptr<A> a5(new A);
+      ASSERT_TRUE(a5.get() != a3);
+      ASSERT_TRUE(a5 != a3.get());
+      a2 = a5;
+      linked_ptr<B> b0(new B);
+      linked_ptr<A> a6(b0);
+      ASSERT_TRUE(b0 == a6);
+      ASSERT_TRUE(a6 == b0);
+      ASSERT_TRUE(b0 != NULL);
+      a5 = b0;
+      a5 = b0;
+      a3->Use();
+      a4->Use();
+      a5->Use();
+      a6->Use();
+      b0->Use();
+      (*b0).Use();
+      b0.get()->Use();
+    }
+
+    a0->Use();
+    a1->Use();
+    a2->Use();
+
+    a1 = a2;
+    a2.reset(new A);
+    a0.reset();
+
+    linked_ptr<A> a7;
+  }
+
+  ASSERT_EQ(history,
+    "A0 ctor\n"
+    "A1 ctor\n"
+    "A2 ctor\n"
+    "B2 ctor\n"
+    "A0 use\n"
+    "A0 use\n"
+    "B2 use\n"
+    "B2 use\n"
+    "B2 use\n"
+    "B2 use\n"
+    "B2 use\n"
+    "B2 dtor\n"
+    "A2 dtor\n"
+    "A0 use\n"
+    "A0 use\n"
+    "A1 use\n"
+    "A3 ctor\n"
+    "A0 dtor\n"
+    "A3 dtor\n"
+    "A1 dtor\n"
+  );
+}
diff --git a/base/memory/memory_debug.cc b/base/memory/memory_debug.cc
new file mode 100644
index 0000000..f020b94
--- /dev/null
+++ b/base/memory/memory_debug.cc
@@ -0,0 +1,54 @@
+// 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/memory_debug.h"
+
+#ifdef PURIFY
+// this #define is used to prevent people from directly using pure.h
+// instead of memory_debug.h
+#define PURIFY_PRIVATE_INCLUDE
+#include "base/third_party/purify/pure.h"
+#endif
+
+namespace base {
+
+bool MemoryDebug::memory_in_use_ = false;
+
+void MemoryDebug::SetMemoryInUseEnabled(bool enabled) {
+  memory_in_use_ = enabled;
+}
+
+void MemoryDebug::DumpAllMemoryInUse() {
+#ifdef PURIFY
+  if (memory_in_use_)
+    PurifyAllInuse();
+#endif
+}
+
+void MemoryDebug::DumpNewMemoryInUse() {
+#ifdef PURIFY
+  if (memory_in_use_)
+    PurifyNewInuse();
+#endif
+}
+
+void MemoryDebug::DumpAllLeaks() {
+#ifdef PURIFY
+  PurifyAllLeaks();
+#endif
+}
+
+void MemoryDebug::DumpNewLeaks() {
+#ifdef PURIFY
+  PurifyNewLeaks();
+#endif
+}
+
+void MemoryDebug::MarkAsInitialized(void* addr, size_t size) {
+#ifdef PURIFY
+  PurifyMarkAsInitialized(addr, size);
+#endif
+}
+
+}  // namespace base
diff --git a/base/memory/memory_debug.h b/base/memory/memory_debug.h
new file mode 100644
index 0000000..9cc6c61
--- /dev/null
+++ b/base/memory/memory_debug.h
@@ -0,0 +1,47 @@
+// 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.
+
+// Functions used to debug memory usage, leaks, and other memory issues.
+// All methods are effectively no-ops unless this program is being run through
+// a supported memory tool (currently, only Purify)
+
+#ifndef BASE_MEMORY_MEMORY_DEBUG_H_
+#define BASE_MEMORY_MEMORY_DEBUG_H_
+#pragma once
+
+#include "base/basictypes.h"
+
+namespace base {
+
+class MemoryDebug {
+ public:
+  // Since MIU messages are a lot of data, and we don't always want this data,
+  // we have a global switch.  If disabled, *MemoryInUse are no-ops.
+  static void SetMemoryInUseEnabled(bool enabled);
+
+  // Dump information about all memory in use.
+  static void DumpAllMemoryInUse();
+  // Dump information about new memory in use since the last
+  // call to DumpAllMemoryInUse() or DumpNewMemoryInUse().
+  static void DumpNewMemoryInUse();
+
+  // Dump information about all current memory leaks.
+  static void DumpAllLeaks();
+  // Dump information about new memory leaks since the last
+  // call to DumpAllLeaks() or DumpNewLeaks()
+  static void DumpNewLeaks();
+
+  // Mark |size| bytes of memory as initialized, so it doesn't produce any UMRs
+  // or UMCs.
+  static void MarkAsInitialized(void* addr, size_t size);
+
+ private:
+  static bool memory_in_use_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(MemoryDebug);
+};
+
+}  // namespace base
+
+#endif  // BASE_MEMORY_MEMORY_DEBUG_H_
diff --git a/base/memory/raw_scoped_refptr_mismatch_checker.h b/base/memory/raw_scoped_refptr_mismatch_checker.h
new file mode 100644
index 0000000..a4a50c3
--- /dev/null
+++ b/base/memory/raw_scoped_refptr_mismatch_checker.h
@@ -0,0 +1,130 @@
+// 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.
+
+#ifndef BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_
+#define BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_
+#pragma once
+
+#include "base/memory/ref_counted.h"
+#include "base/template_util.h"
+#include "base/tuple.h"
+#include "build/build_config.h"
+
+// It is dangerous to post a task with a T* argument where T is a subtype of
+// RefCounted(Base|ThreadSafeBase), since by the time the parameter is used, the
+// object may already have been deleted since it was not held with a
+// scoped_refptr. Example: http://crbug.com/27191
+// The following set of traits are designed to generate a compile error
+// whenever this antipattern is attempted.
+
+namespace base {
+
+// This is a base internal implementation file used by task.h and callback.h.
+// Not for public consumption, so we wrap it in namespace internal.
+namespace internal {
+
+template <typename T>
+struct NeedsScopedRefptrButGetsRawPtr {
+#if defined(OS_WIN)
+  enum {
+    value = base::false_type::value
+  };
+#else
+  enum {
+    // Human readable translation: you needed to be a scoped_refptr if you are a
+    // raw pointer type and are convertible to a RefCounted(Base|ThreadSafeBase)
+    // type.
+    value = (is_pointer<T>::value &&
+             (is_convertible<T, subtle::RefCountedBase*>::value ||
+              is_convertible<T, subtle::RefCountedThreadSafeBase*>::value))
+  };
+#endif
+};
+
+template <typename Params>
+struct ParamsUseScopedRefptrCorrectly {
+  enum { value = 0 };
+};
+
+template <>
+struct ParamsUseScopedRefptrCorrectly<Tuple0> {
+  enum { value = 1 };
+};
+
+template <typename A>
+struct ParamsUseScopedRefptrCorrectly<Tuple1<A> > {
+  enum { value = !NeedsScopedRefptrButGetsRawPtr<A>::value };
+};
+
+template <typename A, typename B>
+struct ParamsUseScopedRefptrCorrectly<Tuple2<A, B> > {
+  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<B>::value) };
+};
+
+template <typename A, typename B, typename C>
+struct ParamsUseScopedRefptrCorrectly<Tuple3<A, B, C> > {
+  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<C>::value) };
+};
+
+template <typename A, typename B, typename C, typename D>
+struct ParamsUseScopedRefptrCorrectly<Tuple4<A, B, C, D> > {
+  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<D>::value) };
+};
+
+template <typename A, typename B, typename C, typename D, typename E>
+struct ParamsUseScopedRefptrCorrectly<Tuple5<A, B, C, D, E> > {
+  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<D>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<E>::value) };
+};
+
+template <typename A, typename B, typename C, typename D, typename E,
+          typename F>
+struct ParamsUseScopedRefptrCorrectly<Tuple6<A, B, C, D, E, F> > {
+  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<D>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<E>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<F>::value) };
+};
+
+template <typename A, typename B, typename C, typename D, typename E,
+          typename F, typename G>
+struct ParamsUseScopedRefptrCorrectly<Tuple7<A, B, C, D, E, F, G> > {
+  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<D>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<E>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<F>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<G>::value) };
+};
+
+template <typename A, typename B, typename C, typename D, typename E,
+          typename F, typename G, typename H>
+struct ParamsUseScopedRefptrCorrectly<Tuple8<A, B, C, D, E, F, G, H> > {
+  enum { value = !(NeedsScopedRefptrButGetsRawPtr<A>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<B>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<C>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<D>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<E>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<F>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<G>::value ||
+                   NeedsScopedRefptrButGetsRawPtr<H>::value) };
+};
+
+}  // namespace internal
+
+}  // namespace base
+
+#endif  // BASE_MEMORY_RAW_SCOPED_REFPTR_MISMATCH_CHECKER_H_
diff --git a/base/memory/ref_counted.cc b/base/memory/ref_counted.cc
new file mode 100644
index 0000000..31ad509
--- /dev/null
+++ b/base/memory/ref_counted.cc
@@ -0,0 +1,95 @@
+// 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/ref_counted.h"
+
+#include "base/logging.h"
+#include "base/threading/thread_collision_warner.h"
+
+namespace base {
+
+namespace subtle {
+
+RefCountedBase::RefCountedBase()
+    : ref_count_(0)
+#ifndef NDEBUG
+    , in_dtor_(false)
+#endif
+    {
+}
+
+RefCountedBase::~RefCountedBase() {
+#ifndef NDEBUG
+  DCHECK(in_dtor_) << "RefCounted object deleted without calling Release()";
+#endif
+}
+
+void RefCountedBase::AddRef() const {
+  // TODO(maruel): Add back once it doesn't assert 500 times/sec.
+  // Current thread books the critical section "AddRelease" without release it.
+  // DFAKE_SCOPED_LOCK_THREAD_LOCKED(add_release_);
+#ifndef NDEBUG
+  DCHECK(!in_dtor_);
+#endif
+  ++ref_count_;
+}
+
+bool RefCountedBase::Release() const {
+  // TODO(maruel): Add back once it doesn't assert 500 times/sec.
+  // Current thread books the critical section "AddRelease" without release it.
+  // DFAKE_SCOPED_LOCK_THREAD_LOCKED(add_release_);
+#ifndef NDEBUG
+  DCHECK(!in_dtor_);
+#endif
+  if (--ref_count_ == 0) {
+#ifndef NDEBUG
+    in_dtor_ = true;
+#endif
+    return true;
+  }
+  return false;
+}
+
+bool RefCountedThreadSafeBase::HasOneRef() const {
+  return AtomicRefCountIsOne(
+      &const_cast<RefCountedThreadSafeBase*>(this)->ref_count_);
+}
+
+RefCountedThreadSafeBase::RefCountedThreadSafeBase() : ref_count_(0) {
+#ifndef NDEBUG
+  in_dtor_ = false;
+#endif
+}
+
+RefCountedThreadSafeBase::~RefCountedThreadSafeBase() {
+#ifndef NDEBUG
+  DCHECK(in_dtor_) << "RefCountedThreadSafe object deleted without "
+                      "calling Release()";
+#endif
+}
+
+void RefCountedThreadSafeBase::AddRef() const {
+#ifndef NDEBUG
+  DCHECK(!in_dtor_);
+#endif
+  AtomicRefCountInc(&ref_count_);
+}
+
+bool RefCountedThreadSafeBase::Release() const {
+#ifndef NDEBUG
+  DCHECK(!in_dtor_);
+  DCHECK(!AtomicRefCountIsZero(&ref_count_));
+#endif
+  if (!AtomicRefCountDec(&ref_count_)) {
+#ifndef NDEBUG
+    in_dtor_ = true;
+#endif
+    return true;
+  }
+  return false;
+}
+
+}  // namespace subtle
+
+}  // namespace base
diff --git a/base/memory/ref_counted.h b/base/memory/ref_counted.h
new file mode 100644
index 0000000..1207ed4
--- /dev/null
+++ b/base/memory/ref_counted.h
@@ -0,0 +1,299 @@
+// 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.
+
+#ifndef BASE_MEMORY_REF_COUNTED_H_
+#define BASE_MEMORY_REF_COUNTED_H_
+#pragma once
+
+#include "base/atomic_ref_count.h"
+#include "base/base_api.h"
+#include "base/threading/thread_collision_warner.h"
+
+namespace base {
+
+namespace subtle {
+
+class BASE_API RefCountedBase {
+ public:
+  static bool ImplementsThreadSafeReferenceCounting() { return false; }
+
+  bool HasOneRef() const { return ref_count_ == 1; }
+
+ protected:
+  RefCountedBase();
+  ~RefCountedBase();
+
+  void AddRef() const;
+
+  // Returns true if the object should self-delete.
+  bool Release() const;
+
+ private:
+  mutable int ref_count_;
+#ifndef NDEBUG
+  mutable bool in_dtor_;
+#endif
+
+  DFAKE_MUTEX(add_release_);
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedBase);
+};
+
+class BASE_API RefCountedThreadSafeBase {
+ public:
+  static bool ImplementsThreadSafeReferenceCounting() { return true; }
+
+  bool HasOneRef() const;
+
+ protected:
+  RefCountedThreadSafeBase();
+  ~RefCountedThreadSafeBase();
+
+  void AddRef() const;
+
+  // Returns true if the object should self-delete.
+  bool Release() const;
+
+ private:
+  mutable AtomicRefCount ref_count_;
+#ifndef NDEBUG
+  mutable bool in_dtor_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedThreadSafeBase);
+};
+
+}  // namespace subtle
+
+//
+// A base class for reference counted classes.  Otherwise, known as a cheap
+// knock-off of WebKit's RefCounted<T> class.  To use this guy just extend your
+// class from it like so:
+//
+//   class MyFoo : public base::RefCounted<MyFoo> {
+//    ...
+//    private:
+//     friend class base::RefCounted<MyFoo>;
+//     ~MyFoo();
+//   };
+//
+// You should always make your destructor private, to avoid any code deleting
+// the object accidently while there are references to it.
+template <class T>
+class RefCounted : public subtle::RefCountedBase {
+ public:
+  RefCounted() { }
+  ~RefCounted() { }
+
+  void AddRef() const {
+    subtle::RefCountedBase::AddRef();
+  }
+
+  void Release() const {
+    if (subtle::RefCountedBase::Release()) {
+      delete static_cast<const T*>(this);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RefCounted<T>);
+};
+
+// Forward declaration.
+template <class T, typename Traits> class RefCountedThreadSafe;
+
+// Default traits for RefCountedThreadSafe<T>.  Deletes the object when its ref
+// count reaches 0.  Overload to delete it on a different thread etc.
+template<typename T>
+struct DefaultRefCountedThreadSafeTraits {
+  static void Destruct(const T* x) {
+    // Delete through RefCountedThreadSafe to make child classes only need to be
+    // friend with RefCountedThreadSafe instead of this struct, which is an
+    // implementation detail.
+    RefCountedThreadSafe<T,
+                         DefaultRefCountedThreadSafeTraits>::DeleteInternal(x);
+  }
+};
+
+//
+// A thread-safe variant of RefCounted<T>
+//
+//   class MyFoo : public base::RefCountedThreadSafe<MyFoo> {
+//    ...
+//   };
+//
+// If you're using the default trait, then you should add compile time
+// asserts that no one else is deleting your object.  i.e.
+//    private:
+//     friend class base::RefCountedThreadSafe<MyFoo>;
+//     ~MyFoo();
+template <class T, typename Traits = DefaultRefCountedThreadSafeTraits<T> >
+class RefCountedThreadSafe : public subtle::RefCountedThreadSafeBase {
+ public:
+  RefCountedThreadSafe() { }
+  ~RefCountedThreadSafe() { }
+
+  void AddRef() const {
+    subtle::RefCountedThreadSafeBase::AddRef();
+  }
+
+  void Release() const {
+    if (subtle::RefCountedThreadSafeBase::Release()) {
+      Traits::Destruct(static_cast<const T*>(this));
+    }
+  }
+
+ private:
+  friend struct DefaultRefCountedThreadSafeTraits<T>;
+  static void DeleteInternal(const T* x) { delete x; }
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedThreadSafe);
+};
+
+//
+// A wrapper for some piece of data so we can place other things in
+// scoped_refptrs<>.
+//
+template<typename T>
+class RefCountedData : public base::RefCounted< base::RefCountedData<T> > {
+ public:
+  RefCountedData() : data() {}
+  RefCountedData(const T& in_value) : data(in_value) {}
+
+  T data;
+};
+
+}  // namespace base
+
+//
+// A smart pointer class for reference counted objects.  Use this class instead
+// of calling AddRef and Release manually on a reference counted object to
+// avoid common memory leaks caused by forgetting to Release an object
+// reference.  Sample usage:
+//
+//   class MyFoo : public RefCounted<MyFoo> {
+//    ...
+//   };
+//
+//   void some_function() {
+//     scoped_refptr<MyFoo> foo = new MyFoo();
+//     foo->Method(param);
+//     // |foo| is released when this function returns
+//   }
+//
+//   void some_other_function() {
+//     scoped_refptr<MyFoo> foo = new MyFoo();
+//     ...
+//     foo = NULL;  // explicitly releases |foo|
+//     ...
+//     if (foo)
+//       foo->Method(param);
+//   }
+//
+// The above examples show how scoped_refptr<T> acts like a pointer to T.
+// Given two scoped_refptr<T> classes, it is also possible to exchange
+// references between the two objects, like so:
+//
+//   {
+//     scoped_refptr<MyFoo> a = new MyFoo();
+//     scoped_refptr<MyFoo> b;
+//
+//     b.swap(a);
+//     // now, |b| references the MyFoo object, and |a| references NULL.
+//   }
+//
+// To make both |a| and |b| in the above example reference the same MyFoo
+// object, simply use the assignment operator:
+//
+//   {
+//     scoped_refptr<MyFoo> a = new MyFoo();
+//     scoped_refptr<MyFoo> b;
+//
+//     b = a;
+//     // now, |a| and |b| each own a reference to the same MyFoo object.
+//   }
+//
+template <class T>
+class scoped_refptr {
+ public:
+  scoped_refptr() : ptr_(NULL) {
+  }
+
+  scoped_refptr(T* p) : ptr_(p) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  scoped_refptr(const scoped_refptr<T>& r) : ptr_(r.ptr_) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  template <typename U>
+  scoped_refptr(const scoped_refptr<U>& r) : ptr_(r.get()) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  ~scoped_refptr() {
+    if (ptr_)
+      ptr_->Release();
+  }
+
+  T* get() const { return ptr_; }
+  operator T*() const { return ptr_; }
+  T* operator->() const { return ptr_; }
+
+  // Release a pointer.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  T* release() {
+    T* retVal = ptr_;
+    ptr_ = NULL;
+    return retVal;
+  }
+
+  scoped_refptr<T>& operator=(T* p) {
+    // AddRef first so that self assignment should work
+    if (p)
+      p->AddRef();
+    if (ptr_ )
+      ptr_ ->Release();
+    ptr_ = p;
+    return *this;
+  }
+
+  scoped_refptr<T>& operator=(const scoped_refptr<T>& r) {
+    return *this = r.ptr_;
+  }
+
+  template <typename U>
+  scoped_refptr<T>& operator=(const scoped_refptr<U>& r) {
+    return *this = r.get();
+  }
+
+  void swap(T** pp) {
+    T* p = ptr_;
+    ptr_ = *pp;
+    *pp = p;
+  }
+
+  void swap(scoped_refptr<T>& r) {
+    swap(&r.ptr_);
+  }
+
+ protected:
+  T* ptr_;
+};
+
+// Handy utility for creating a scoped_refptr<T> out of a T* explicitly without
+// having to retype all the template arguments
+template <typename T>
+scoped_refptr<T> make_scoped_refptr(T* t) {
+  return scoped_refptr<T>(t);
+}
+
+#endif  // BASE_MEMORY_REF_COUNTED_H_
diff --git a/base/memory/ref_counted_memory.cc b/base/memory/ref_counted_memory.cc
new file mode 100644
index 0000000..aa16031
--- /dev/null
+++ b/base/memory/ref_counted_memory.cc
@@ -0,0 +1,46 @@
+// 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/ref_counted_memory.h"
+
+RefCountedMemory::RefCountedMemory() {
+}
+
+RefCountedMemory::~RefCountedMemory() {
+}
+
+const unsigned char* RefCountedStaticMemory::front() const {
+  return data_;
+}
+
+size_t RefCountedStaticMemory::size() const {
+  return length_;
+}
+
+RefCountedBytes::RefCountedBytes() {
+}
+
+RefCountedBytes::RefCountedBytes(const std::vector<unsigned char>& initializer)
+    : data(initializer) {
+}
+
+RefCountedBytes* RefCountedBytes::TakeVector(
+    std::vector<unsigned char>* to_destroy) {
+  RefCountedBytes* bytes = new RefCountedBytes;
+  bytes->data.swap(*to_destroy);
+  return bytes;
+}
+
+const unsigned char* RefCountedBytes::front() const {
+  // STL will assert if we do front() on an empty vector, but calling code
+  // expects a NULL.
+  return size() ? &data.front() : NULL;
+}
+
+size_t RefCountedBytes::size() const {
+  return data.size();
+}
+
+RefCountedBytes::~RefCountedBytes() {
+}
diff --git a/base/memory/ref_counted_memory.h b/base/memory/ref_counted_memory.h
new file mode 100644
index 0000000..db15792
--- /dev/null
+++ b/base/memory/ref_counted_memory.h
@@ -0,0 +1,82 @@
+// 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.
+
+#ifndef BASE_MEMORY_REF_COUNTED_MEMORY_H_
+#define BASE_MEMORY_REF_COUNTED_MEMORY_H_
+#pragma once
+
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+
+// TODO(erg): The contents of this file should be in a namespace. This would
+// require touching >100 files in chrome/ though.
+
+// A generic interface to memory. This object is reference counted because one
+// of its two subclasses own the data they carry, and we need to have
+// heterogeneous containers of these two types of memory.
+class RefCountedMemory : public base::RefCountedThreadSafe<RefCountedMemory> {
+ public:
+  // Retrieves a pointer to the beginning of the data we point to. If the data
+  // is empty, this will return NULL.
+  virtual const unsigned char* front() const = 0;
+
+  // Size of the memory pointed to.
+  virtual size_t size() const = 0;
+
+ protected:
+  friend class base::RefCountedThreadSafe<RefCountedMemory>;
+  RefCountedMemory();
+  virtual ~RefCountedMemory();
+};
+
+// An implementation of RefCountedMemory, where the ref counting does not
+// matter.
+class RefCountedStaticMemory : public RefCountedMemory {
+ public:
+  RefCountedStaticMemory()
+      : data_(NULL), length_(0) {}
+  RefCountedStaticMemory(const unsigned char* data, size_t length)
+      : data_(data), length_(length) {}
+
+  // Overriden from RefCountedMemory:
+  virtual const unsigned char* front() const;
+  virtual size_t size() const;
+
+ private:
+  const unsigned char* data_;
+  size_t length_;
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedStaticMemory);
+};
+
+// An implementation of RefCountedMemory, where we own our the data in a
+// vector.
+class RefCountedBytes : public RefCountedMemory {
+ public:
+  RefCountedBytes();
+
+  // Constructs a RefCountedBytes object by _copying_ from |initializer|.
+  RefCountedBytes(const std::vector<unsigned char>& initializer);
+
+  // Constructs a RefCountedBytes object by performing a swap. (To non
+  // destructively build a RefCountedBytes, use the constructor that takes a
+  // vector.)
+  static RefCountedBytes* TakeVector(std::vector<unsigned char>* to_destroy);
+
+  // Overriden from RefCountedMemory:
+  virtual const unsigned char* front() const;
+  virtual size_t size() const;
+
+  std::vector<unsigned char> data;
+
+ protected:
+  friend class base::RefCountedThreadSafe<RefCountedBytes>;
+  virtual ~RefCountedBytes();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RefCountedBytes);
+};
+
+#endif  // BASE_MEMORY_REF_COUNTED_MEMORY_H_
diff --git a/base/memory/ref_counted_unittest.cc b/base/memory/ref_counted_unittest.cc
new file mode 100644
index 0000000..dcc292f
--- /dev/null
+++ b/base/memory/ref_counted_unittest.cc
@@ -0,0 +1,36 @@
+// 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/ref_counted.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class SelfAssign : public base::RefCounted<SelfAssign> {
+  friend class base::RefCounted<SelfAssign>;
+
+  ~SelfAssign() {}
+};
+
+class CheckDerivedMemberAccess : public scoped_refptr<SelfAssign> {
+ public:
+  CheckDerivedMemberAccess() {
+    // This shouldn't compile if we don't have access to the member variable.
+    SelfAssign** pptr = &ptr_;
+    EXPECT_EQ(*pptr, ptr_);
+  }
+};
+
+}  // end namespace
+
+TEST(RefCountedUnitTest, TestSelfAssignment) {
+  SelfAssign* p = new SelfAssign;
+  scoped_refptr<SelfAssign> var(p);
+  var = var;
+  EXPECT_EQ(var.get(), p);
+}
+
+TEST(RefCountedUnitTest, ScopedRefPtrMemberAccess) {
+  CheckDerivedMemberAccess check;
+}
diff --git a/base/memory/scoped_callback_factory.h b/base/memory/scoped_callback_factory.h
new file mode 100644
index 0000000..a9c58a0
--- /dev/null
+++ b/base/memory/scoped_callback_factory.h
@@ -0,0 +1,133 @@
+// 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.
+
+// ScopedCallbackFactory helps in cases where you wish to allocate a Callback
+// (see base/callback.h), but need to prevent any pending callbacks from
+// executing when your object gets destroyed.
+//
+// EXAMPLE:
+//
+//  void GatherDataAsynchronously(Callback1<Data>::Type* callback);
+//
+//  class MyClass {
+//   public:
+//    MyClass() : factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+//    }
+//
+//    void Process() {
+//      GatherDataAsynchronously(factory_.NewCallback(&MyClass::GotData));
+//    }
+//
+//   private:
+//    void GotData(const Data& data) {
+//      ...
+//    }
+//
+//    base::ScopedCallbackFactory<MyClass> factory_;
+//  };
+//
+// In the above example, the Process function calls GatherDataAsynchronously to
+// kick off some asynchronous processing that upon completion will notify a
+// callback.  If in the meantime, the MyClass instance is destroyed, when the
+// callback runs, it will notice that the MyClass instance is dead, and it will
+// avoid calling the GotData method.
+
+#ifndef BASE_MEMORY_SCOPED_CALLBACK_FACTORY_H_
+#define BASE_MEMORY_SCOPED_CALLBACK_FACTORY_H_
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+
+namespace base {
+
+template <class T>
+class ScopedCallbackFactory {
+ public:
+  explicit ScopedCallbackFactory(T* obj) : weak_factory_(obj) {
+  }
+
+  typename Callback0::Type* NewCallback(
+      void (T::*method)()) {
+    return new CallbackImpl<void (T::*)(), Tuple0 >(
+        weak_factory_.GetWeakPtr(), method);
+  }
+
+  template <typename Arg1>
+  typename Callback1<Arg1>::Type* NewCallback(
+      void (T::*method)(Arg1)) {
+    return new CallbackImpl<void (T::*)(Arg1), Tuple1<Arg1> >(
+        weak_factory_.GetWeakPtr(), method);
+  }
+
+  template <typename Arg1, typename Arg2>
+  typename Callback2<Arg1, Arg2>::Type* NewCallback(
+      void (T::*method)(Arg1, Arg2)) {
+    return new CallbackImpl<void (T::*)(Arg1, Arg2), Tuple2<Arg1, Arg2> >(
+        weak_factory_.GetWeakPtr(), method);
+  }
+
+  template <typename Arg1, typename Arg2, typename Arg3>
+  typename Callback3<Arg1, Arg2, Arg3>::Type* NewCallback(
+      void (T::*method)(Arg1, Arg2, Arg3)) {
+    return new CallbackImpl<void (T::*)(Arg1, Arg2, Arg3),
+                            Tuple3<Arg1, Arg2, Arg3> >(
+        weak_factory_.GetWeakPtr(), method);
+  }
+
+  template <typename Arg1, typename Arg2, typename Arg3, typename Arg4>
+  typename Callback4<Arg1, Arg2, Arg3, Arg4>::Type* NewCallback(
+      void (T::*method)(Arg1, Arg2, Arg3, Arg4)) {
+    return new CallbackImpl<void (T::*)(Arg1, Arg2, Arg3, Arg4),
+                            Tuple4<Arg1, Arg2, Arg3, Arg4> >(
+        weak_factory_.GetWeakPtr(), method);
+  }
+
+  template <typename Arg1, typename Arg2, typename Arg3, typename Arg4,
+            typename Arg5>
+  typename Callback5<Arg1, Arg2, Arg3, Arg4, Arg5>::Type* NewCallback(
+      void (T::*method)(Arg1, Arg2, Arg3, Arg4, Arg5)) {
+    return new CallbackImpl<void (T::*)(Arg1, Arg2, Arg3, Arg4, Arg5),
+                            Tuple5<Arg1, Arg2, Arg3, Arg4, Arg5> >(
+        weak_factory_.GetWeakPtr(), method);
+  }
+
+  void RevokeAll() { weak_factory_.InvalidateWeakPtrs(); }
+  bool HasPendingCallbacks() const { return weak_factory_.HasWeakPtrs(); }
+
+ private:
+  template <typename Method>
+  class CallbackStorage {
+   public:
+    CallbackStorage(const WeakPtr<T>& obj, Method meth)
+        : obj_(obj),
+          meth_(meth) {
+    }
+
+   protected:
+    WeakPtr<T> obj_;
+    Method meth_;
+  };
+
+  template <typename Method, typename Params>
+  class CallbackImpl : public CallbackStorage<Method>,
+                       public CallbackRunner<Params> {
+   public:
+    CallbackImpl(const WeakPtr<T>& obj, Method meth)
+        : CallbackStorage<Method>(obj, meth) {
+    }
+    virtual void RunWithParams(const Params& params) {
+      // Use "this->" to force C++ to look inside our templatized base class;
+      // see Effective C++, 3rd Ed, item 43, p210 for details.
+      if (!this->obj_)
+        return;
+      DispatchToMethod(this->obj_.get(), this->meth_, params);
+    }
+  };
+
+  WeakPtrFactory<T> weak_factory_;
+};
+
+}  // namespace base
+
+#endif  // BASE_MEMORY_SCOPED_CALLBACK_FACTORY_H_
diff --git a/base/memory/scoped_handle.h b/base/memory/scoped_handle.h
new file mode 100644
index 0000000..232d83e
--- /dev/null
+++ b/base/memory/scoped_handle.h
@@ -0,0 +1,51 @@
+// 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.
+
+#ifndef BASE_MEMORY_SCOPED_HANDLE_H_
+#define BASE_MEMORY_SCOPED_HANDLE_H_
+#pragma once
+
+#include <stdio.h>
+
+#include "base/basictypes.h"
+
+class ScopedStdioHandle {
+ public:
+  ScopedStdioHandle()
+      : handle_(NULL) { }
+
+  explicit ScopedStdioHandle(FILE* handle)
+      : handle_(handle) { }
+
+  ~ScopedStdioHandle() {
+    Close();
+  }
+
+  void Close() {
+    if (handle_) {
+      fclose(handle_);
+      handle_ = NULL;
+    }
+  }
+
+  FILE* get() const { return handle_; }
+
+  FILE* Take() {
+    FILE* temp = handle_;
+    handle_ = NULL;
+    return temp;
+  }
+
+  void Set(FILE* newhandle) {
+    Close();
+    handle_ = newhandle;
+  }
+
+ private:
+  FILE* handle_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedStdioHandle);
+};
+
+#endif  // BASE_MEMORY_SCOPED_HANDLE_H_
diff --git a/base/memory/scoped_native_library.cc b/base/memory/scoped_native_library.cc
new file mode 100644
index 0000000..c9aef45
--- /dev/null
+++ b/base/memory/scoped_native_library.cc
@@ -0,0 +1,44 @@
+// 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/scoped_native_library.h"
+
+namespace base {
+
+ScopedNativeLibrary::ScopedNativeLibrary() : library_(NULL) {
+}
+
+ScopedNativeLibrary::ScopedNativeLibrary(NativeLibrary library)
+    : library_(library) {
+}
+
+ScopedNativeLibrary::ScopedNativeLibrary(const FilePath& library_path) {
+  library_ = base::LoadNativeLibrary(library_path);
+}
+
+ScopedNativeLibrary::~ScopedNativeLibrary() {
+  if (library_)
+    base::UnloadNativeLibrary(library_);
+}
+
+void* ScopedNativeLibrary::GetFunctionPointer(
+    const char* function_name) const {
+  if (!library_)
+    return NULL;
+  return base::GetFunctionPointerFromNativeLibrary(library_, function_name);
+}
+
+void ScopedNativeLibrary::Reset(NativeLibrary library) {
+  if (library_)
+    base::UnloadNativeLibrary(library_);
+  library_ = library;
+}
+
+NativeLibrary ScopedNativeLibrary::Release() {
+  NativeLibrary result = library_;
+  library_ = NULL;
+  return result;
+}
+
+}  // namespace base
diff --git a/base/memory/scoped_native_library.h b/base/memory/scoped_native_library.h
new file mode 100644
index 0000000..56116b9
--- /dev/null
+++ b/base/memory/scoped_native_library.h
@@ -0,0 +1,53 @@
+// 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.
+
+#ifndef BASE_MEMORY_SCOPED_NATIVE_LIBRARY_H_
+#define BASE_MEMORY_SCOPED_NATIVE_LIBRARY_H_
+#pragma once
+
+#include "base/base_api.h"
+#include "base/native_library.h"
+
+class FilePath;
+
+namespace base {
+
+// A class which encapsulates a base::NativeLibrary object available only in a
+// scope.
+// This class automatically unloads the loaded library in its destructor.
+class BASE_API ScopedNativeLibrary {
+ public:
+  // Initializes with a NULL library.
+  ScopedNativeLibrary();
+
+  // Takes ownership of the given library handle.
+  explicit ScopedNativeLibrary(NativeLibrary library);
+
+  // Opens the given library and manages its lifetime.
+  explicit ScopedNativeLibrary(const FilePath& library_path);
+
+  ~ScopedNativeLibrary();
+
+  // Returns true if there's a valid library loaded.
+  bool is_valid() const { return !!library_; }
+
+  void* GetFunctionPointer(const char* function_name) const;
+
+  // Takes ownership of the given library handle. Any existing handle will
+  // be freed.
+  void Reset(NativeLibrary library);
+
+  // Returns the native library handle and removes it from this object. The
+  // caller must manage the lifetime of the handle.
+  NativeLibrary Release();
+
+ private:
+  NativeLibrary library_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedNativeLibrary);
+};
+
+}  // namespace base
+
+#endif  // BASE_MEMORY_SCOPED_NATIVE_LIBRARY_H_
diff --git a/base/memory/scoped_native_library_unittest.cc b/base/memory/scoped_native_library_unittest.cc
new file mode 100644
index 0000000..0cc60e2
--- /dev/null
+++ b/base/memory/scoped_native_library_unittest.cc
@@ -0,0 +1,33 @@
+// 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/scoped_native_library.h"
+#if defined(OS_WIN)
+#include "base/file_path.h"
+#endif
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+// Tests whether or not a function pointer retrieved via ScopedNativeLibrary
+// is available only in a scope.
+TEST(ScopedNativeLibrary, Basic) {
+#if defined(OS_WIN)
+  // Get the pointer to DirectDrawCreate() from "ddraw.dll" and verify it
+  // is valid only in this scope.
+  // FreeLibrary() doesn't actually unload a DLL until its reference count
+  // becomes zero, i.e. this function pointer is still valid if the DLL used
+  // in this test is also used by another part of this executable.
+  // So, this test uses "ddraw.dll", which is not used by Chrome at all but
+  // installed on all versions of Windows.
+  FARPROC test_function;
+  {
+    FilePath path(base::GetNativeLibraryName(L"ddraw"));
+    base::ScopedNativeLibrary library(path);
+    test_function = reinterpret_cast<FARPROC>(
+        library.GetFunctionPointer("DirectDrawCreate"));
+    EXPECT_EQ(0, IsBadCodePtr(test_function));
+  }
+  EXPECT_NE(0, IsBadCodePtr(test_function));
+#endif
+}
diff --git a/base/memory/scoped_nsobject.h b/base/memory/scoped_nsobject.h
new file mode 100644
index 0000000..235ac39
--- /dev/null
+++ b/base/memory/scoped_nsobject.h
@@ -0,0 +1,167 @@
+// 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.
+
+#ifndef BASE_MEMORY_SCOPED_NSOBJECT_H_
+#define BASE_MEMORY_SCOPED_NSOBJECT_H_
+#pragma once
+
+#import <Foundation/Foundation.h>
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+
+// scoped_nsobject<> is patterned after scoped_ptr<>, but maintains ownership
+// of an NSObject subclass object.  Style deviations here are solely for
+// compatibility with scoped_ptr<>'s interface, with which everyone is already
+// familiar.
+//
+// When scoped_nsobject<> takes ownership of an object (in the constructor or
+// in reset()), it takes over the caller's existing ownership claim.  The
+// caller must own the object it gives to scoped_nsobject<>, and relinquishes
+// an ownership claim to that object.  scoped_nsobject<> does not call
+// -retain.
+//
+// scoped_nsobject<> is not to be used for NSAutoreleasePools. For
+// NSAutoreleasePools use ScopedNSAutoreleasePool from
+// scoped_nsautorelease_pool.h instead.
+// We check for bad uses of scoped_nsobject and NSAutoreleasePool at compile
+// time with a template specialization (see below).
+template<typename NST>
+class scoped_nsobject {
+ public:
+  typedef NST* element_type;
+
+  explicit scoped_nsobject(NST* object = nil)
+      : object_(object) {
+  }
+
+  ~scoped_nsobject() {
+    [object_ release];
+  }
+
+  void reset(NST* object = nil) {
+    // We intentionally do not check that object != object_ as the caller must
+    // already have an ownership claim over whatever it gives to
+    // scoped_nsobject and ScopedCFTypeRef, whether it's in the constructor or
+    // in a call to reset().  In either case, it relinquishes that claim and
+    // the scoper assumes it.
+    [object_ release];
+    object_ = object;
+  }
+
+  bool operator==(NST* that) const { return object_ == that; }
+  bool operator!=(NST* that) const { return object_ != that; }
+
+  operator NST*() const {
+    return object_;
+  }
+
+  NST* get() const {
+    return object_;
+  }
+
+  void swap(scoped_nsobject& that) {
+    NST* temp = that.object_;
+    that.object_ = object_;
+    object_ = temp;
+  }
+
+  // scoped_nsobject<>::release() is like scoped_ptr<>::release.  It is NOT
+  // a wrapper for [object_ release].  To force a scoped_nsobject<> object to
+  // call [object_ release], use scoped_nsobject<>::reset().
+  NST* release() WARN_UNUSED_RESULT {
+    NST* temp = object_;
+    object_ = nil;
+    return temp;
+  }
+
+ private:
+  NST* object_;
+
+  DISALLOW_COPY_AND_ASSIGN(scoped_nsobject);
+};
+
+// Free functions
+template <class C>
+void swap(scoped_nsobject<C>& p1, scoped_nsobject<C>& p2) {
+  p1.swap(p2);
+}
+
+template <class C>
+bool operator==(C* p1, const scoped_nsobject<C>& p2) {
+  return p1 == p2.get();
+}
+
+template <class C>
+bool operator!=(C* p1, const scoped_nsobject<C>& p2) {
+  return p1 != p2.get();
+}
+
+
+// Specialization to make scoped_nsobject<id> work.
+template<>
+class scoped_nsobject<id> {
+ public:
+  typedef id element_type;
+
+  explicit scoped_nsobject(id object = nil)
+      : object_(object) {
+  }
+
+  ~scoped_nsobject() {
+    [object_ release];
+  }
+
+  void reset(id object = nil) {
+    // We intentionally do not check that object != object_ as the caller must
+    // already have an ownership claim over whatever it gives to
+    // scoped_nsobject and ScopedCFTypeRef, whether it's in the constructor or
+    // in a call to reset().  In either case, it relinquishes that claim and
+    // the scoper assumes it.
+    [object_ release];
+    object_ = object;
+  }
+
+  bool operator==(id that) const { return object_ == that; }
+  bool operator!=(id that) const { return object_ != that; }
+
+  operator id() const {
+    return object_;
+  }
+
+  id get() const {
+    return object_;
+  }
+
+  void swap(scoped_nsobject& that) {
+    id temp = that.object_;
+    that.object_ = object_;
+    object_ = temp;
+  }
+
+  // scoped_nsobject<>::release() is like scoped_ptr<>::release.  It is NOT
+  // a wrapper for [object_ release].  To force a scoped_nsobject<> object to
+  // call [object_ release], use scoped_nsobject<>::reset().
+  id release() WARN_UNUSED_RESULT {
+    id temp = object_;
+    object_ = nil;
+    return temp;
+  }
+
+ private:
+  id object_;
+
+  DISALLOW_COPY_AND_ASSIGN(scoped_nsobject);
+};
+
+// Do not use scoped_nsobject for NSAutoreleasePools, use
+// ScopedNSAutoreleasePool instead. This is a compile time check. See details
+// at top of header.
+template<>
+class scoped_nsobject<NSAutoreleasePool> {
+ private:
+  explicit scoped_nsobject(NSAutoreleasePool* object = nil);
+  DISALLOW_COPY_AND_ASSIGN(scoped_nsobject);
+};
+
+#endif  // BASE_MEMORY_SCOPED_NSOBJECT_H_
diff --git a/base/memory/scoped_open_process.h b/base/memory/scoped_open_process.h
new file mode 100644
index 0000000..d5bdd95
--- /dev/null
+++ b/base/memory/scoped_open_process.h
@@ -0,0 +1,50 @@
+// 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.
+
+#ifndef BASE_MEMORY_SCOPED_OPEN_PROCESS_H_
+#define BASE_MEMORY_SCOPED_OPEN_PROCESS_H_
+#pragma once
+
+#include "base/process.h"
+#include "base/process_util.h"
+
+namespace base {
+
+// A class that opens a process from its process id and closes it when the
+// instance goes out of scope.
+class ScopedOpenProcess {
+ public:
+  ScopedOpenProcess() : handle_(kNullProcessHandle) {
+  }
+
+  // Automatically close the process.
+  ~ScopedOpenProcess() {
+    Close();
+  }
+
+  // Open a new process by pid. Closes any previously opened process (even if
+  // opening the new one fails).
+  bool Open(ProcessId pid) {
+    Close();
+    return OpenProcessHandle(pid, &handle_);
+  }
+
+  // Close the previously opened process.
+  void Close() {
+    if (handle_ == kNullProcessHandle)
+      return;
+
+    CloseProcessHandle(handle_);
+    handle_ = kNullProcessHandle;
+  }
+
+  ProcessHandle handle() const { return handle_; }
+
+ private:
+  ProcessHandle handle_;
+  DISALLOW_COPY_AND_ASSIGN(ScopedOpenProcess);
+};
+}  // namespace base
+
+#endif  // BASE_MEMORY_SCOPED_OPEN_PROCESS_H_
diff --git a/base/memory/scoped_ptr.h b/base/memory/scoped_ptr.h
new file mode 100644
index 0000000..1067d42
--- /dev/null
+++ b/base/memory/scoped_ptr.h
@@ -0,0 +1,383 @@
+// 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.
+
+// Scopers help you manage ownership of a pointer, helping you easily manage the
+// a pointer within a scope, and automatically destroying the pointer at the
+// end of a scope.  There are two main classes you will use, which correspond
+// to the operators new/delete and new[]/delete[].
+//
+// Example usage (scoped_ptr):
+//   {
+//     scoped_ptr<Foo> foo(new Foo("wee"));
+//   }  // foo goes out of scope, releasing the pointer with it.
+//
+//   {
+//     scoped_ptr<Foo> foo;          // No pointer managed.
+//     foo.reset(new Foo("wee"));    // Now a pointer is managed.
+//     foo.reset(new Foo("wee2"));   // Foo("wee") was destroyed.
+//     foo.reset(new Foo("wee3"));   // Foo("wee2") was destroyed.
+//     foo->Method();                // Foo::Method() called.
+//     foo.get()->Method();          // Foo::Method() called.
+//     SomeFunc(foo.release());      // SomeFunc takes ownership, foo no longer
+//                                   // manages a pointer.
+//     foo.reset(new Foo("wee4"));   // foo manages a pointer again.
+//     foo.reset();                  // Foo("wee4") destroyed, foo no longer
+//                                   // manages a pointer.
+//   }  // foo wasn't managing a pointer, so nothing was destroyed.
+//
+// Example usage (scoped_array):
+//   {
+//     scoped_array<Foo> foo(new Foo[100]);
+//     foo.get()->Method();  // Foo::Method on the 0th element.
+//     foo[10].Method();     // Foo::Method on the 10th element.
+//   }
+
+#ifndef BASE_MEMORY_SCOPED_PTR_H_
+#define BASE_MEMORY_SCOPED_PTR_H_
+#pragma once
+
+// This is an implementation designed to match the anticipated future TR2
+// implementation of the scoped_ptr class, and its closely-related brethren,
+// scoped_array, scoped_ptr_malloc.
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+
+#include "base/compiler_specific.h"
+
+// A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
+// automatically deletes the pointer it holds (if any).
+// That is, scoped_ptr<T> owns the T object that it points to.
+// Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
+// Also like T*, scoped_ptr<T> is thread-compatible, and once you
+// dereference it, you get the threadsafety guarantees of T.
+//
+// The size of a scoped_ptr is small:
+// sizeof(scoped_ptr<C>) == sizeof(C*)
+template <class C>
+class scoped_ptr {
+ public:
+
+  // The element type
+  typedef C element_type;
+
+  // Constructor.  Defaults to initializing with NULL.
+  // There is no way to create an uninitialized scoped_ptr.
+  // The input parameter must be allocated with new.
+  explicit scoped_ptr(C* p = NULL) : ptr_(p) { }
+
+  // Destructor.  If there is a C object, delete it.
+  // We don't need to test ptr_ == NULL because C++ does that for us.
+  ~scoped_ptr() {
+    enum { type_must_be_complete = sizeof(C) };
+    delete ptr_;
+  }
+
+  // Reset.  Deletes the current owned object, if any.
+  // Then takes ownership of a new object, if given.
+  // this->reset(this->get()) works.
+  void reset(C* p = NULL) {
+    if (p != ptr_) {
+      enum { type_must_be_complete = sizeof(C) };
+      delete ptr_;
+      ptr_ = p;
+    }
+  }
+
+  // Accessors to get the owned object.
+  // operator* and operator-> will assert() if there is no current object.
+  C& operator*() const {
+    assert(ptr_ != NULL);
+    return *ptr_;
+  }
+  C* operator->() const  {
+    assert(ptr_ != NULL);
+    return ptr_;
+  }
+  C* get() const { return ptr_; }
+
+  // Comparison operators.
+  // These return whether two scoped_ptr refer to the same object, not just to
+  // two different but equal objects.
+  bool operator==(C* p) const { return ptr_ == p; }
+  bool operator!=(C* p) const { return ptr_ != p; }
+
+  // Swap two scoped pointers.
+  void swap(scoped_ptr& p2) {
+    C* tmp = ptr_;
+    ptr_ = p2.ptr_;
+    p2.ptr_ = tmp;
+  }
+
+  // Release a pointer.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  C* release() WARN_UNUSED_RESULT {
+    C* retVal = ptr_;
+    ptr_ = NULL;
+    return retVal;
+  }
+
+ private:
+  C* ptr_;
+
+  // Forbid comparison of scoped_ptr types.  If C2 != C, it totally doesn't
+  // make sense, and if C2 == C, it still doesn't make sense because you should
+  // never have the same object owned by two different scoped_ptrs.
+  template <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
+  template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;
+
+  // Disallow evil constructors
+  scoped_ptr(const scoped_ptr&);
+  void operator=(const scoped_ptr&);
+};
+
+// Free functions
+template <class C>
+void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) {
+  p1.swap(p2);
+}
+
+template <class C>
+bool operator==(C* p1, const scoped_ptr<C>& p2) {
+  return p1 == p2.get();
+}
+
+template <class C>
+bool operator!=(C* p1, const scoped_ptr<C>& p2) {
+  return p1 != p2.get();
+}
+
+// scoped_array<C> is like scoped_ptr<C>, except that the caller must allocate
+// with new [] and the destructor deletes objects with delete [].
+//
+// As with scoped_ptr<C>, a scoped_array<C> either points to an object
+// or is NULL.  A scoped_array<C> owns the object that it points to.
+// scoped_array<T> is thread-compatible, and once you index into it,
+// the returned objects have only the threadsafety guarantees of T.
+//
+// Size: sizeof(scoped_array<C>) == sizeof(C*)
+template <class C>
+class scoped_array {
+ public:
+
+  // The element type
+  typedef C element_type;
+
+  // Constructor.  Defaults to intializing with NULL.
+  // There is no way to create an uninitialized scoped_array.
+  // The input parameter must be allocated with new [].
+  explicit scoped_array(C* p = NULL) : array_(p) { }
+
+  // Destructor.  If there is a C object, delete it.
+  // We don't need to test ptr_ == NULL because C++ does that for us.
+  ~scoped_array() {
+    enum { type_must_be_complete = sizeof(C) };
+    delete[] array_;
+  }
+
+  // Reset.  Deletes the current owned object, if any.
+  // Then takes ownership of a new object, if given.
+  // this->reset(this->get()) works.
+  void reset(C* p = NULL) {
+    if (p != array_) {
+      enum { type_must_be_complete = sizeof(C) };
+      delete[] array_;
+      array_ = p;
+    }
+  }
+
+  // Get one element of the current object.
+  // Will assert() if there is no current object, or index i is negative.
+  C& operator[](ptrdiff_t i) const {
+    assert(i >= 0);
+    assert(array_ != NULL);
+    return array_[i];
+  }
+
+  // Get a pointer to the zeroth element of the current object.
+  // If there is no current object, return NULL.
+  C* get() const {
+    return array_;
+  }
+
+  // Comparison operators.
+  // These return whether two scoped_array refer to the same object, not just to
+  // two different but equal objects.
+  bool operator==(C* p) const { return array_ == p; }
+  bool operator!=(C* p) const { return array_ != p; }
+
+  // Swap two scoped arrays.
+  void swap(scoped_array& p2) {
+    C* tmp = array_;
+    array_ = p2.array_;
+    p2.array_ = tmp;
+  }
+
+  // Release an array.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  C* release() WARN_UNUSED_RESULT {
+    C* retVal = array_;
+    array_ = NULL;
+    return retVal;
+  }
+
+ private:
+  C* array_;
+
+  // Forbid comparison of different scoped_array types.
+  template <class C2> bool operator==(scoped_array<C2> const& p2) const;
+  template <class C2> bool operator!=(scoped_array<C2> const& p2) const;
+
+  // Disallow evil constructors
+  scoped_array(const scoped_array&);
+  void operator=(const scoped_array&);
+};
+
+// Free functions
+template <class C>
+void swap(scoped_array<C>& p1, scoped_array<C>& p2) {
+  p1.swap(p2);
+}
+
+template <class C>
+bool operator==(C* p1, const scoped_array<C>& p2) {
+  return p1 == p2.get();
+}
+
+template <class C>
+bool operator!=(C* p1, const scoped_array<C>& p2) {
+  return p1 != p2.get();
+}
+
+// This class wraps the c library function free() in a class that can be
+// passed as a template argument to scoped_ptr_malloc below.
+class ScopedPtrMallocFree {
+ public:
+  inline void operator()(void* x) const {
+    free(x);
+  }
+};
+
+// scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a
+// second template argument, the functor used to free the object.
+
+template<class C, class FreeProc = ScopedPtrMallocFree>
+class scoped_ptr_malloc {
+ public:
+
+  // The element type
+  typedef C element_type;
+
+  // Constructor.  Defaults to initializing with NULL.
+  // There is no way to create an uninitialized scoped_ptr.
+  // The input parameter must be allocated with an allocator that matches the
+  // Free functor.  For the default Free functor, this is malloc, calloc, or
+  // realloc.
+  explicit scoped_ptr_malloc(C* p = NULL): ptr_(p) {}
+
+  // Destructor.  If there is a C object, call the Free functor.
+  ~scoped_ptr_malloc() {
+    free_(ptr_);
+  }
+
+  // Reset.  Calls the Free functor on the current owned object, if any.
+  // Then takes ownership of a new object, if given.
+  // this->reset(this->get()) works.
+  void reset(C* p = NULL) {
+    if (ptr_ != p) {
+      free_(ptr_);
+      ptr_ = p;
+    }
+  }
+
+  // Get the current object.
+  // operator* and operator-> will cause an assert() failure if there is
+  // no current object.
+  C& operator*() const {
+    assert(ptr_ != NULL);
+    return *ptr_;
+  }
+
+  C* operator->() const {
+    assert(ptr_ != NULL);
+    return ptr_;
+  }
+
+  C* get() const {
+    return ptr_;
+  }
+
+  // Comparison operators.
+  // These return whether a scoped_ptr_malloc and a plain pointer refer
+  // to the same object, not just to two different but equal objects.
+  // For compatibility with the boost-derived implementation, these
+  // take non-const arguments.
+  bool operator==(C* p) const {
+    return ptr_ == p;
+  }
+
+  bool operator!=(C* p) const {
+    return ptr_ != p;
+  }
+
+  // Swap two scoped pointers.
+  void swap(scoped_ptr_malloc & b) {
+    C* tmp = b.ptr_;
+    b.ptr_ = ptr_;
+    ptr_ = tmp;
+  }
+
+  // Release a pointer.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  C* release() WARN_UNUSED_RESULT {
+    C* tmp = ptr_;
+    ptr_ = NULL;
+    return tmp;
+  }
+
+ private:
+  C* ptr_;
+
+  // no reason to use these: each scoped_ptr_malloc should have its own object
+  template <class C2, class GP>
+  bool operator==(scoped_ptr_malloc<C2, GP> const& p) const;
+  template <class C2, class GP>
+  bool operator!=(scoped_ptr_malloc<C2, GP> const& p) const;
+
+  static FreeProc const free_;
+
+  // Disallow evil constructors
+  scoped_ptr_malloc(const scoped_ptr_malloc&);
+  void operator=(const scoped_ptr_malloc&);
+};
+
+template<class C, class FP>
+FP const scoped_ptr_malloc<C, FP>::free_ = FP();
+
+template<class C, class FP> inline
+void swap(scoped_ptr_malloc<C, FP>& a, scoped_ptr_malloc<C, FP>& b) {
+  a.swap(b);
+}
+
+template<class C, class FP> inline
+bool operator==(C* p, const scoped_ptr_malloc<C, FP>& b) {
+  return p == b.get();
+}
+
+template<class C, class FP> inline
+bool operator!=(C* p, const scoped_ptr_malloc<C, FP>& b) {
+  return p != b.get();
+}
+
+#endif  // BASE_MEMORY_SCOPED_PTR_H_
diff --git a/base/memory/scoped_ptr_unittest.cc b/base/memory/scoped_ptr_unittest.cc
new file mode 100644
index 0000000..7519051
--- /dev/null
+++ b/base/memory/scoped_ptr_unittest.cc
@@ -0,0 +1,169 @@
+// 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/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class ConDecLogger {
+ public:
+  ConDecLogger() : ptr_(NULL) { }
+  explicit ConDecLogger(int* ptr) { set_ptr(ptr); }
+  ~ConDecLogger() { --*ptr_; }
+
+  void set_ptr(int* ptr) { ptr_ = ptr; ++*ptr_; }
+
+  int SomeMeth(int x) { return x; }
+
+ private:
+  int* ptr_;
+  DISALLOW_COPY_AND_ASSIGN(ConDecLogger);
+};
+
+}  // namespace
+
+TEST(ScopedPtrTest, ScopedPtr) {
+  int constructed = 0;
+
+  {
+    scoped_ptr<ConDecLogger> scoper(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+
+    EXPECT_EQ(10, scoper->SomeMeth(10));
+    EXPECT_EQ(10, scoper.get()->SomeMeth(10));
+    EXPECT_EQ(10, (*scoper).SomeMeth(10));
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test reset() and release()
+  {
+    scoped_ptr<ConDecLogger> scoper(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+
+    scoper.reset(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+
+    scoper.reset();
+    EXPECT_EQ(0, constructed);
+    EXPECT_FALSE(scoper.get());
+
+    scoper.reset(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+
+    ConDecLogger* take = scoper.release();
+    EXPECT_EQ(1, constructed);
+    EXPECT_FALSE(scoper.get());
+    delete take;
+    EXPECT_EQ(0, constructed);
+
+    scoper.reset(new ConDecLogger(&constructed));
+    EXPECT_EQ(1, constructed);
+    EXPECT_TRUE(scoper.get());
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test swap(), == and !=
+  {
+    scoped_ptr<ConDecLogger> scoper1;
+    scoped_ptr<ConDecLogger> scoper2;
+    EXPECT_TRUE(scoper1 == scoper2.get());
+    EXPECT_FALSE(scoper1 != scoper2.get());
+
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    scoper1.reset(logger);
+    EXPECT_EQ(logger, scoper1.get());
+    EXPECT_FALSE(scoper2.get());
+    EXPECT_FALSE(scoper1 == scoper2.get());
+    EXPECT_TRUE(scoper1 != scoper2.get());
+
+    scoper2.swap(scoper1);
+    EXPECT_EQ(logger, scoper2.get());
+    EXPECT_FALSE(scoper1.get());
+    EXPECT_FALSE(scoper1 == scoper2.get());
+    EXPECT_TRUE(scoper1 != scoper2.get());
+  }
+  EXPECT_EQ(0, constructed);
+}
+
+TEST(ScopedPtrTest, ScopedArray) {
+  static const int kNumLoggers = 12;
+
+  int constructed = 0;
+
+  {
+    scoped_array<ConDecLogger> scoper(new ConDecLogger[kNumLoggers]);
+    EXPECT_TRUE(scoper.get());
+    EXPECT_EQ(&scoper[0], scoper.get());
+    for (int i = 0; i < kNumLoggers; ++i) {
+      scoper[i].set_ptr(&constructed);
+    }
+    EXPECT_EQ(12, constructed);
+
+    EXPECT_EQ(10, scoper.get()->SomeMeth(10));
+    EXPECT_EQ(10, scoper[2].SomeMeth(10));
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test reset() and release()
+  {
+    scoped_array<ConDecLogger> scoper;
+    EXPECT_FALSE(scoper.get());
+    EXPECT_FALSE(scoper.release());
+    EXPECT_FALSE(scoper.get());
+    scoper.reset();
+    EXPECT_FALSE(scoper.get());
+
+    scoper.reset(new ConDecLogger[kNumLoggers]);
+    for (int i = 0; i < kNumLoggers; ++i) {
+      scoper[i].set_ptr(&constructed);
+    }
+    EXPECT_EQ(12, constructed);
+    scoper.reset();
+    EXPECT_EQ(0, constructed);
+
+    scoper.reset(new ConDecLogger[kNumLoggers]);
+    for (int i = 0; i < kNumLoggers; ++i) {
+      scoper[i].set_ptr(&constructed);
+    }
+    EXPECT_EQ(12, constructed);
+    ConDecLogger* ptr = scoper.release();
+    EXPECT_EQ(12, constructed);
+    delete[] ptr;
+    EXPECT_EQ(0, constructed);
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test swap(), == and !=
+  {
+    scoped_array<ConDecLogger> scoper1;
+    scoped_array<ConDecLogger> scoper2;
+    EXPECT_TRUE(scoper1 == scoper2.get());
+    EXPECT_FALSE(scoper1 != scoper2.get());
+
+    ConDecLogger* loggers = new ConDecLogger[kNumLoggers];
+    for (int i = 0; i < kNumLoggers; ++i) {
+      loggers[i].set_ptr(&constructed);
+    }
+    scoper1.reset(loggers);
+    EXPECT_EQ(loggers, scoper1.get());
+    EXPECT_FALSE(scoper2.get());
+    EXPECT_FALSE(scoper1 == scoper2.get());
+    EXPECT_TRUE(scoper1 != scoper2.get());
+
+    scoper2.swap(scoper1);
+    EXPECT_EQ(loggers, scoper2.get());
+    EXPECT_FALSE(scoper1.get());
+    EXPECT_FALSE(scoper1 == scoper2.get());
+    EXPECT_TRUE(scoper1 != scoper2.get());
+  }
+  EXPECT_EQ(0, constructed);
+}
+
+// TODO scoped_ptr_malloc
diff --git a/base/memory/scoped_temp_dir.cc b/base/memory/scoped_temp_dir.cc
new file mode 100644
index 0000000..f7db15d
--- /dev/null
+++ b/base/memory/scoped_temp_dir.cc
@@ -0,0 +1,84 @@
+// 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/scoped_temp_dir.h"
+
+#include "base/file_util.h"
+#include "base/logging.h"
+
+ScopedTempDir::ScopedTempDir() {
+}
+
+ScopedTempDir::~ScopedTempDir() {
+  if (!path_.empty() && !Delete())
+    LOG(WARNING) << "Could not delete temp dir in dtor.";
+}
+
+bool ScopedTempDir::CreateUniqueTempDir() {
+  if (!path_.empty())
+    return false;
+
+  // This "scoped_dir" prefix is only used on Windows and serves as a template
+  // for the unique name.
+  if (!file_util::CreateNewTempDirectory(FILE_PATH_LITERAL("scoped_dir"),
+                                         &path_))
+    return false;
+
+  return true;
+}
+
+bool ScopedTempDir::CreateUniqueTempDirUnderPath(const FilePath& base_path) {
+  if (!path_.empty())
+    return false;
+
+  // If |base_path| does not exist, create it.
+  if (!file_util::CreateDirectory(base_path))
+    return false;
+
+  // Create a new, uniquely named directory under |base_path|.
+  if (!file_util::CreateTemporaryDirInDir(
+          base_path,
+          FILE_PATH_LITERAL("scoped_dir_"),
+          &path_))
+    return false;
+
+  return true;
+}
+
+bool ScopedTempDir::Set(const FilePath& path) {
+  if (!path_.empty())
+    return false;
+
+  if (!file_util::DirectoryExists(path) &&
+      !file_util::CreateDirectory(path))
+    return false;
+
+  path_ = path;
+  return true;
+}
+
+bool ScopedTempDir::Delete() {
+  if (path_.empty())
+    return false;
+
+  bool ret = file_util::Delete(path_, true);
+  if (ret) {
+    // We only clear the path if deleted the directory.
+    path_.clear();
+  } else {
+    LOG(ERROR) << "ScopedTempDir unable to delete " << path_.value();
+  }
+
+  return ret;
+}
+
+FilePath ScopedTempDir::Take() {
+  FilePath ret = path_;
+  path_ = FilePath();
+  return ret;
+}
+
+bool ScopedTempDir::IsValid() const {
+  return !path_.empty() && file_util::DirectoryExists(path_);
+}
diff --git a/base/memory/scoped_temp_dir.h b/base/memory/scoped_temp_dir.h
new file mode 100644
index 0000000..4c0a73f
--- /dev/null
+++ b/base/memory/scoped_temp_dir.h
@@ -0,0 +1,59 @@
+// 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.
+
+#ifndef BASE_MEMORY_SCOPED_TEMP_DIR_H_
+#define BASE_MEMORY_SCOPED_TEMP_DIR_H_
+#pragma once
+
+// An object representing a temporary / scratch directory that should be cleaned
+// up (recursively) when this object goes out of scope.  Note that since
+// deletion occurs during the destructor, no further error handling is possible
+// if the directory fails to be deleted.  As a result, deletion is not
+// guaranteed by this class.
+//
+// Multiple calls to the methods which establish a temporary directory
+// (CreateUniqueTempDir, CreateUniqueTempDirUnderPath, and Set) must have
+// intervening calls to Delete or Take, or the calls will fail.
+
+#include "base/base_api.h"
+#include "base/file_path.h"
+
+class BASE_API ScopedTempDir {
+ public:
+  // No directory is owned/created initially.
+  ScopedTempDir();
+
+  // Recursively delete path.
+  ~ScopedTempDir();
+
+  // Creates a unique directory in TempPath, and takes ownership of it.
+  // See file_util::CreateNewTemporaryDirectory.
+  bool CreateUniqueTempDir() WARN_UNUSED_RESULT;
+
+  // Creates a unique directory under a given path, and takes ownership of it.
+  bool CreateUniqueTempDirUnderPath(const FilePath& path) WARN_UNUSED_RESULT;
+
+  // Takes ownership of directory at |path|, creating it if necessary.
+  // Don't call multiple times unless Take() has been called first.
+  bool Set(const FilePath& path) WARN_UNUSED_RESULT;
+
+  // Deletes the temporary directory wrapped by this object.
+  bool Delete() WARN_UNUSED_RESULT;
+
+  // Caller takes ownership of the temporary directory so it won't be destroyed
+  // when this object goes out of scope.
+  FilePath Take();
+
+  const FilePath& path() const { return path_; }
+
+  // Returns true if path_ is non-empty and exists.
+  bool IsValid() const;
+
+ private:
+  FilePath path_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedTempDir);
+};
+
+#endif  // BASE_MEMORY_SCOPED_TEMP_DIR_H_
diff --git a/base/memory/scoped_temp_dir_unittest.cc b/base/memory/scoped_temp_dir_unittest.cc
new file mode 100644
index 0000000..a83856f
--- /dev/null
+++ b/base/memory/scoped_temp_dir_unittest.cc
@@ -0,0 +1,110 @@
+// 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/file_util.h"
+#include "base/memory/scoped_temp_dir.h"
+#include "base/platform_file.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(ScopedTempDir, FullPath) {
+  FilePath test_path;
+  file_util::CreateNewTempDirectory(FILE_PATH_LITERAL("scoped_temp_dir"),
+                                    &test_path);
+
+  // Against an existing dir, it should get destroyed when leaving scope.
+  EXPECT_TRUE(file_util::DirectoryExists(test_path));
+  {
+    ScopedTempDir dir;
+    EXPECT_TRUE(dir.Set(test_path));
+    EXPECT_TRUE(dir.IsValid());
+  }
+  EXPECT_FALSE(file_util::DirectoryExists(test_path));
+
+  {
+    ScopedTempDir dir;
+    EXPECT_TRUE(dir.Set(test_path));
+    // Now the dir doesn't exist, so ensure that it gets created.
+    EXPECT_TRUE(file_util::DirectoryExists(test_path));
+    // When we call Release(), it shouldn't get destroyed when leaving scope.
+    FilePath path = dir.Take();
+    EXPECT_EQ(path.value(), test_path.value());
+    EXPECT_FALSE(dir.IsValid());
+  }
+  EXPECT_TRUE(file_util::DirectoryExists(test_path));
+
+  // Clean up.
+  {
+    ScopedTempDir dir;
+    EXPECT_TRUE(dir.Set(test_path));
+  }
+  EXPECT_FALSE(file_util::DirectoryExists(test_path));
+}
+
+TEST(ScopedTempDir, TempDir) {
+  // In this case, just verify that a directory was created and that it's a
+  // child of TempDir.
+  FilePath test_path;
+  {
+    ScopedTempDir dir;
+    EXPECT_TRUE(dir.CreateUniqueTempDir());
+    test_path = dir.path();
+    EXPECT_TRUE(file_util::DirectoryExists(test_path));
+    FilePath tmp_dir;
+    EXPECT_TRUE(file_util::GetTempDir(&tmp_dir));
+    EXPECT_TRUE(test_path.value().find(tmp_dir.value()) != std::string::npos);
+  }
+  EXPECT_FALSE(file_util::DirectoryExists(test_path));
+}
+
+TEST(ScopedTempDir, UniqueTempDirUnderPath) {
+  // Create a path which will contain a unique temp path.
+  FilePath base_path;
+  file_util::CreateNewTempDirectory(FILE_PATH_LITERAL("base_dir"),
+                                    &base_path);
+
+  FilePath test_path;
+  {
+    ScopedTempDir dir;
+    EXPECT_TRUE(dir.CreateUniqueTempDirUnderPath(base_path));
+    test_path = dir.path();
+    EXPECT_TRUE(file_util::DirectoryExists(test_path));
+    EXPECT_TRUE(base_path.IsParent(test_path));
+    EXPECT_TRUE(test_path.value().find(base_path.value()) != std::string::npos);
+  }
+  EXPECT_FALSE(file_util::DirectoryExists(test_path));
+}
+
+TEST(ScopedTempDir, MultipleInvocations) {
+  ScopedTempDir dir;
+  EXPECT_TRUE(dir.CreateUniqueTempDir());
+  EXPECT_FALSE(dir.CreateUniqueTempDir());
+  EXPECT_TRUE(dir.Delete());
+  EXPECT_TRUE(dir.CreateUniqueTempDir());
+  EXPECT_FALSE(dir.CreateUniqueTempDir());
+  ScopedTempDir other_dir;
+  EXPECT_TRUE(other_dir.Set(dir.Take()));
+  EXPECT_TRUE(dir.CreateUniqueTempDir());
+  EXPECT_FALSE(dir.CreateUniqueTempDir());
+  EXPECT_FALSE(other_dir.CreateUniqueTempDir());
+}
+
+#if defined(OS_WIN)
+TEST(ScopedTempDir, LockedTempDir) {
+  ScopedTempDir dir;
+  EXPECT_TRUE(dir.CreateUniqueTempDir());
+  int file_flags = base::PLATFORM_FILE_CREATE_ALWAYS |
+                   base::PLATFORM_FILE_WRITE;
+  base::PlatformFileError error_code = base::PLATFORM_FILE_OK;
+  FilePath file_path(dir.path().Append(FILE_PATH_LITERAL("temp")));
+  base::PlatformFile file = base::CreatePlatformFile(file_path, file_flags,
+                                                     NULL, &error_code);
+  EXPECT_NE(base::kInvalidPlatformFileValue, file);
+  EXPECT_EQ(base::PLATFORM_FILE_OK, error_code);
+  EXPECT_FALSE(dir.Delete());  // We should not be able to delete.
+  EXPECT_FALSE(dir.path().empty());  // We should still have a valid path.
+  EXPECT_TRUE(base::ClosePlatformFile(file));
+  // Now, we should be able to delete.
+  EXPECT_TRUE(dir.Delete());
+}
+#endif  // defined(OS_WIN)
diff --git a/base/memory/scoped_vector.h b/base/memory/scoped_vector.h
new file mode 100644
index 0000000..aec4375
--- /dev/null
+++ b/base/memory/scoped_vector.h
@@ -0,0 +1,90 @@
+// 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.
+
+#ifndef BASE_MEMORY_SCOPED_VECTOR_H_
+#define BASE_MEMORY_SCOPED_VECTOR_H_
+#pragma once
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/stl_util-inl.h"
+
+// ScopedVector wraps a vector deleting the elements from its
+// destructor.
+template <class T>
+class ScopedVector {
+ public:
+  typedef typename std::vector<T*>::iterator iterator;
+  typedef typename std::vector<T*>::const_iterator const_iterator;
+  typedef typename std::vector<T*>::reverse_iterator reverse_iterator;
+  typedef typename std::vector<T*>::const_reverse_iterator
+      const_reverse_iterator;
+
+  ScopedVector() {}
+  ~ScopedVector() { reset(); }
+
+  std::vector<T*>* operator->() { return &v; }
+  const std::vector<T*>* operator->() const { return &v; }
+  T*& operator[](size_t i) { return v[i]; }
+  const T* operator[](size_t i) const { return v[i]; }
+
+  bool empty() const { return v.empty(); }
+  size_t size() const { return v.size(); }
+
+  reverse_iterator rbegin() { return v.rbegin(); }
+  const_reverse_iterator rbegin() const { return v.rbegin(); }
+  reverse_iterator rend() { return v.rend(); }
+  const_reverse_iterator rend() const { return v.rend(); }
+
+  iterator begin() { return v.begin(); }
+  const_iterator begin() const { return v.begin(); }
+  iterator end() { return v.end(); }
+  const_iterator end() const { return v.end(); }
+
+  void push_back(T* elem) { v.push_back(elem); }
+
+  std::vector<T*>& get() { return v; }
+  const std::vector<T*>& get() const { return v; }
+  void swap(ScopedVector<T>& other) { v.swap(other.v); }
+  void release(std::vector<T*>* out) {
+    out->swap(v);
+    v.clear();
+  }
+
+  void reset() { STLDeleteElements(&v); }
+  void reserve(size_t capacity) { v.reserve(capacity); }
+  void resize(size_t new_size) { v.resize(new_size); }
+
+  // Lets the ScopedVector take ownership of |x|.
+  iterator insert(iterator position, T* x) {
+    return v.insert(position, x);
+  }
+
+  iterator erase(iterator position) {
+    delete *position;
+    return v.erase(position);
+  }
+
+  iterator erase(iterator first, iterator last) {
+    STLDeleteContainerPointers(first, last);
+    return v.erase(first, last);
+  }
+
+  // Like |erase()|, but doesn't delete the element at |position|.
+  iterator weak_erase(iterator position) {
+    return v.erase(position);
+  }
+
+  // Like |erase()|, but doesn't delete the elements in [first, last).
+  iterator weak_erase(iterator first, iterator last) {
+    return v.erase(first, last);
+  }
+ private:
+  std::vector<T*> v;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedVector);
+};
+
+#endif  // BASE_MEMORY_SCOPED_VECTOR_H_
diff --git a/base/memory/singleton.h b/base/memory/singleton.h
new file mode 100644
index 0000000..a387356
--- /dev/null
+++ b/base/memory/singleton.h
@@ -0,0 +1,271 @@
+// 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.
+
+#ifndef BASE_MEMORY_SINGLETON_H_
+#define BASE_MEMORY_SINGLETON_H_
+#pragma once
+
+#include "base/at_exit.h"
+#include "base/atomicops.h"
+#include "base/third_party/dynamic_annotations/dynamic_annotations.h"
+#include "base/threading/platform_thread.h"
+#include "base/threading/thread_restrictions.h"
+
+// Default traits for Singleton<Type>. Calls operator new and operator delete on
+// the object. Registers automatic deletion at process exit.
+// Overload if you need arguments or another memory allocation function.
+template<typename Type>
+struct DefaultSingletonTraits {
+  // Allocates the object.
+  static Type* New() {
+    // The parenthesis is very important here; it forces POD type
+    // initialization.
+    return new Type();
+  }
+
+  // Destroys the object.
+  static void Delete(Type* x) {
+    delete x;
+  }
+
+  // Set to true to automatically register deletion of the object on process
+  // exit. See below for the required call that makes this happen.
+  static const bool kRegisterAtExit = true;
+
+  // Set to false to disallow access on a non-joinable thread.  This is
+  // different from kRegisterAtExit because StaticMemorySingletonTraits allows
+  // access on non-joinable threads, and gracefully handles this.
+  static const bool kAllowedToAccessOnNonjoinableThread = false;
+};
+
+
+// Alternate traits for use with the Singleton<Type>.  Identical to
+// DefaultSingletonTraits except that the Singleton will not be cleaned up
+// at exit.
+template<typename Type>
+struct LeakySingletonTraits : public DefaultSingletonTraits<Type> {
+  static const bool kRegisterAtExit = false;
+  static const bool kAllowedToAccessOnNonjoinableThread = true;
+};
+
+
+// Alternate traits for use with the Singleton<Type>.  Allocates memory
+// for the singleton instance from a static buffer.  The singleton will
+// be cleaned up at exit, but can't be revived after destruction unless
+// the Resurrect() method is called.
+//
+// This is useful for a certain category of things, notably logging and
+// tracing, where the singleton instance is of a type carefully constructed to
+// be safe to access post-destruction.
+// In logging and tracing you'll typically get stray calls at odd times, like
+// during static destruction, thread teardown and the like, and there's a
+// termination race on the heap-based singleton - e.g. if one thread calls
+// get(), but then another thread initiates AtExit processing, the first thread
+// may call into an object residing in unallocated memory. If the instance is
+// allocated from the data segment, then this is survivable.
+//
+// The destructor is to deallocate system resources, in this case to unregister
+// a callback the system will invoke when logging levels change. Note that
+// this is also used in e.g. Chrome Frame, where you have to allow for the
+// possibility of loading briefly into someone else's process space, and
+// so leaking is not an option, as that would sabotage the state of your host
+// process once you've unloaded.
+template <typename Type>
+struct StaticMemorySingletonTraits {
+  // WARNING: User has to deal with get() in the singleton class
+  // this is traits for returning NULL.
+  static Type* New() {
+    if (base::subtle::NoBarrier_AtomicExchange(&dead_, 1))
+      return NULL;
+    Type* ptr = reinterpret_cast<Type*>(buffer_);
+
+    // We are protected by a memory barrier.
+    new(ptr) Type();
+    return ptr;
+  }
+
+  static void Delete(Type* p) {
+    base::subtle::NoBarrier_Store(&dead_, 1);
+    base::subtle::MemoryBarrier();
+    if (p != NULL)
+      p->Type::~Type();
+  }
+
+  static const bool kRegisterAtExit = true;
+  static const bool kAllowedToAccessOnNonjoinableThread = true;
+
+  // Exposed for unittesting.
+  static void Resurrect() {
+    base::subtle::NoBarrier_Store(&dead_, 0);
+  }
+
+ private:
+  static const size_t kBufferSize = (sizeof(Type) +
+                                     sizeof(intptr_t) - 1) / sizeof(intptr_t);
+  static intptr_t buffer_[kBufferSize];
+
+  // Signal the object was already deleted, so it is not revived.
+  static base::subtle::Atomic32 dead_;
+};
+
+template <typename Type> intptr_t
+    StaticMemorySingletonTraits<Type>::buffer_[kBufferSize];
+template <typename Type> base::subtle::Atomic32
+    StaticMemorySingletonTraits<Type>::dead_ = 0;
+
+// The Singleton<Type, Traits, DifferentiatingType> class manages a single
+// instance of Type which will be created on first use and will be destroyed at
+// normal process exit). The Trait::Delete function will not be called on
+// abnormal process exit.
+//
+// DifferentiatingType is used as a key to differentiate two different
+// singletons having the same memory allocation functions but serving a
+// different purpose. This is mainly used for Locks serving different purposes.
+//
+// Example usage:
+//
+// In your header:
+//   #include "base/memory/singleton.h"
+//   class FooClass {
+//    public:
+//     static FooClass* GetInstance();  <-- See comment below on this.
+//     void Bar() { ... }
+//    private:
+//     FooClass() { ... }
+//     friend struct DefaultSingletonTraits<FooClass>;
+//
+//     DISALLOW_COPY_AND_ASSIGN(FooClass);
+//   };
+//
+// In your source file:
+//  FooClass* FooClass::GetInstance() {
+//    return Singleton<FooClass>::get();
+//  }
+//
+// And to call methods on FooClass:
+//   FooClass::GetInstance()->Bar();
+//
+// NOTE: The method accessing Singleton<T>::get() has to be named as GetInstance
+// and it is important that FooClass::GetInstance() is not inlined in the
+// header. This makes sure that when source files from multiple targets include
+// this header they don't end up with different copies of the inlined code
+// creating multiple copies of the singleton.
+//
+// Singleton<> has no non-static members and doesn't need to actually be
+// instantiated.
+//
+// This class is itself thread-safe. The underlying Type must of course be
+// thread-safe if you want to use it concurrently. Two parameters may be tuned
+// depending on the user's requirements.
+//
+// Glossary:
+//   RAE = kRegisterAtExit
+//
+// On every platform, if Traits::RAE is true, the singleton will be destroyed at
+// process exit. More precisely it uses base::AtExitManager which requires an
+// object of this type to be instantiated. AtExitManager mimics the semantics
+// of atexit() such as LIFO order but under Windows is safer to call. For more
+// information see at_exit.h.
+//
+// If Traits::RAE is false, the singleton will not be freed at process exit,
+// thus the singleton will be leaked if it is ever accessed. Traits::RAE
+// shouldn't be false unless absolutely necessary. Remember that the heap where
+// the object is allocated may be destroyed by the CRT anyway.
+//
+// Caveats:
+// (a) Every call to get(), operator->() and operator*() incurs some overhead
+//     (16ns on my P4/2.8GHz) to check whether the object has already been
+//     initialized.  You may wish to cache the result of get(); it will not
+//     change.
+//
+// (b) Your factory function must never throw an exception. This class is not
+//     exception-safe.
+//
+template <typename Type,
+          typename Traits = DefaultSingletonTraits<Type>,
+          typename DifferentiatingType = Type>
+class Singleton {
+ private:
+  // Classes using the Singleton<T> pattern should declare a GetInstance()
+  // method and call Singleton::get() from within that.
+  friend Type* Type::GetInstance();
+
+  // This class is safe to be constructed and copy-constructed since it has no
+  // member.
+
+  // Return a pointer to the one true instance of the class.
+  static Type* get() {
+    if (!Traits::kAllowedToAccessOnNonjoinableThread)
+      base::ThreadRestrictions::AssertSingletonAllowed();
+
+    // Our AtomicWord doubles as a spinlock, where a value of
+    // kBeingCreatedMarker means the spinlock is being held for creation.
+    static const base::subtle::AtomicWord kBeingCreatedMarker = 1;
+
+    base::subtle::AtomicWord value = base::subtle::NoBarrier_Load(&instance_);
+    if (value != 0 && value != kBeingCreatedMarker) {
+      // See the corresponding HAPPENS_BEFORE below.
+      ANNOTATE_HAPPENS_AFTER(&instance_);
+      return reinterpret_cast<Type*>(value);
+    }
+
+    // Object isn't created yet, maybe we will get to create it, let's try...
+    if (base::subtle::Acquire_CompareAndSwap(&instance_,
+                                             0,
+                                             kBeingCreatedMarker) == 0) {
+      // instance_ was NULL and is now kBeingCreatedMarker.  Only one thread
+      // will ever get here.  Threads might be spinning on us, and they will
+      // stop right after we do this store.
+      Type* newval = Traits::New();
+
+      // This annotation helps race detectors recognize correct lock-less
+      // synchronization between different threads calling get().
+      // See the corresponding HAPPENS_AFTER below and above.
+      ANNOTATE_HAPPENS_BEFORE(&instance_);
+      base::subtle::Release_Store(
+          &instance_, reinterpret_cast<base::subtle::AtomicWord>(newval));
+
+      if (newval != NULL && Traits::kRegisterAtExit)
+        base::AtExitManager::RegisterCallback(OnExit, NULL);
+
+      return newval;
+    }
+
+    // We hit a race.  Another thread beat us and either:
+    // - Has the object in BeingCreated state
+    // - Already has the object created...
+    // We know value != NULL.  It could be kBeingCreatedMarker, or a valid ptr.
+    // Unless your constructor can be very time consuming, it is very unlikely
+    // to hit this race.  When it does, we just spin and yield the thread until
+    // the object has been created.
+    while (true) {
+      value = base::subtle::NoBarrier_Load(&instance_);
+      if (value != kBeingCreatedMarker)
+        break;
+      base::PlatformThread::YieldCurrentThread();
+    }
+
+    // See the corresponding HAPPENS_BEFORE above.
+    ANNOTATE_HAPPENS_AFTER(&instance_);
+    return reinterpret_cast<Type*>(value);
+  }
+
+  // Adapter function for use with AtExit().  This should be called single
+  // threaded, so don't use atomic operations.
+  // Calling OnExit while singleton is in use by other threads is a mistake.
+  static void OnExit(void* /*unused*/) {
+    // AtExit should only ever be register after the singleton instance was
+    // created.  We should only ever get here with a valid instance_ pointer.
+    Traits::Delete(
+        reinterpret_cast<Type*>(base::subtle::NoBarrier_Load(&instance_)));
+    instance_ = 0;
+  }
+  static base::subtle::AtomicWord instance_;
+};
+
+template <typename Type, typename Traits, typename DifferentiatingType>
+base::subtle::AtomicWord Singleton<Type, Traits, DifferentiatingType>::
+    instance_ = 0;
+
+#endif  // BASE_MEMORY_SINGLETON_H_
diff --git a/base/memory/singleton_objc.h b/base/memory/singleton_objc.h
new file mode 100644
index 0000000..8531556
--- /dev/null
+++ b/base/memory/singleton_objc.h
@@ -0,0 +1,61 @@
+// 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.
+
+// Support for using the Singleton<T> pattern with Objective-C objects.  A
+// SingletonObjC is the same as a Singleton, except the default traits are
+// appropriate for Objective-C objects.  A typical Objective-C object of type
+// NSExampleType can be maintained as a singleton and accessed with:
+//
+//   NSExampleType* exampleSingleton = SingletonObjC<NSExampleType>::get();
+//
+// The first time this is used, it will create exampleSingleton as the result
+// of [[NSExampleType alloc] init].  Subsequent calls will return the same
+// NSExampleType* object.  The object will be released by calling
+// -[NSExampleType release] when Singleton's atexit routines run
+// (see singleton.h).
+//
+// For Objective-C objects initialized through means other than the
+// no-parameter -init selector, DefaultSingletonObjCTraits may be extended
+// as needed:
+//
+//   struct FooSingletonTraits : public DefaultSingletonObjCTraits<Foo> {
+//     static Foo* New() {
+//       return [[Foo alloc] initWithName:@"selecty"];
+//     }
+//   };
+//   ...
+//   Foo* widgetSingleton = SingletonObjC<Foo, FooSingletonTraits>::get();
+
+#ifndef BASE_MEMORY_SINGLETON_OBJC_H_
+#define BASE_MEMORY_SINGLETON_OBJC_H_
+#pragma once
+
+#import <Foundation/Foundation.h>
+#include "base/memory/singleton.h"
+
+// Singleton traits usable to manage traditional Objective-C objects, which
+// are instantiated by sending |alloc| and |init| messages, and are deallocated
+// in a memory-managed environment when their retain counts drop to 0 by
+// sending |release| messages.
+template<typename Type>
+struct DefaultSingletonObjCTraits : public DefaultSingletonTraits<Type> {
+  static Type* New() {
+    return [[Type alloc] init];
+  }
+
+  static void Delete(Type* object) {
+    [object release];
+  }
+};
+
+// Exactly like Singleton, but without the DefaultSingletonObjCTraits as the
+// default trait class.  This makes it straightforward for Objective-C++ code
+// to hold Objective-C objects as singletons.
+template<typename Type,
+         typename Traits = DefaultSingletonObjCTraits<Type>,
+         typename DifferentiatingType = Type>
+class SingletonObjC : public Singleton<Type, Traits, DifferentiatingType> {
+};
+
+#endif  // BASE_MEMORY_SINGLETON_OBJC_H_
diff --git a/base/memory/singleton_unittest.cc b/base/memory/singleton_unittest.cc
new file mode 100644
index 0000000..a605885
--- /dev/null
+++ b/base/memory/singleton_unittest.cc
@@ -0,0 +1,256 @@
+// 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/at_exit.h"
+#include "base/file_util.h"
+#include "base/memory/singleton.h"
+#include "base/path_service.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+COMPILE_ASSERT(DefaultSingletonTraits<int>::kRegisterAtExit == true, a);
+
+typedef void (*CallbackFunc)();
+
+class IntSingleton {
+ public:
+  static IntSingleton* GetInstance() {
+    return Singleton<IntSingleton>::get();
+  }
+
+  int value_;
+};
+
+class Init5Singleton {
+ public:
+  struct Trait;
+
+  static Init5Singleton* GetInstance() {
+    return Singleton<Init5Singleton, Trait>::get();
+  }
+
+  int value_;
+};
+
+struct Init5Singleton::Trait : public DefaultSingletonTraits<Init5Singleton> {
+  static Init5Singleton* New() {
+    Init5Singleton* instance = new Init5Singleton();
+    instance->value_ = 5;
+    return instance;
+  }
+};
+
+int* SingletonInt() {
+  return &IntSingleton::GetInstance()->value_;
+}
+
+int* SingletonInt5() {
+  return &Init5Singleton::GetInstance()->value_;
+}
+
+template <typename Type>
+struct CallbackTrait : public DefaultSingletonTraits<Type> {
+  static void Delete(Type* instance) {
+    if (instance->callback_)
+      (instance->callback_)();
+    DefaultSingletonTraits<Type>::Delete(instance);
+  }
+};
+
+class CallbackSingleton {
+ public:
+  CallbackSingleton() : callback_(NULL) { }
+  CallbackFunc callback_;
+};
+
+class CallbackSingletonWithNoLeakTrait : public CallbackSingleton {
+ public:
+  struct Trait : public CallbackTrait<CallbackSingletonWithNoLeakTrait> { };
+
+  CallbackSingletonWithNoLeakTrait() : CallbackSingleton() { }
+
+  static CallbackSingletonWithNoLeakTrait* GetInstance() {
+    return Singleton<CallbackSingletonWithNoLeakTrait, Trait>::get();
+  }
+};
+
+class CallbackSingletonWithLeakTrait : public CallbackSingleton {
+ public:
+  struct Trait : public CallbackTrait<CallbackSingletonWithLeakTrait> {
+    static const bool kRegisterAtExit = false;
+  };
+
+  CallbackSingletonWithLeakTrait() : CallbackSingleton() { }
+
+  static CallbackSingletonWithLeakTrait* GetInstance() {
+    return Singleton<CallbackSingletonWithLeakTrait, Trait>::get();
+  }
+};
+
+class CallbackSingletonWithStaticTrait : public CallbackSingleton {
+ public:
+  struct Trait;
+
+  CallbackSingletonWithStaticTrait() : CallbackSingleton() { }
+
+  static CallbackSingletonWithStaticTrait* GetInstance() {
+    return Singleton<CallbackSingletonWithStaticTrait, Trait>::get();
+  }
+};
+
+struct CallbackSingletonWithStaticTrait::Trait
+    : public StaticMemorySingletonTraits<CallbackSingletonWithStaticTrait> {
+  static void Delete(CallbackSingletonWithStaticTrait* instance) {
+    if (instance->callback_)
+      (instance->callback_)();
+    StaticMemorySingletonTraits<CallbackSingletonWithStaticTrait>::Delete(
+        instance);
+  }
+};
+
+
+void SingletonNoLeak(CallbackFunc CallOnQuit) {
+  CallbackSingletonWithNoLeakTrait::GetInstance()->callback_ = CallOnQuit;
+}
+
+void SingletonLeak(CallbackFunc CallOnQuit) {
+  CallbackSingletonWithLeakTrait::GetInstance()->callback_ = CallOnQuit;
+}
+
+CallbackFunc* GetLeakySingleton() {
+  return &CallbackSingletonWithLeakTrait::GetInstance()->callback_;
+}
+
+void DeleteLeakySingleton() {
+  DefaultSingletonTraits<CallbackSingletonWithLeakTrait>::Delete(
+      CallbackSingletonWithLeakTrait::GetInstance());
+}
+
+void SingletonStatic(CallbackFunc CallOnQuit) {
+  CallbackSingletonWithStaticTrait::GetInstance()->callback_ = CallOnQuit;
+}
+
+CallbackFunc* GetStaticSingleton() {
+  return &CallbackSingletonWithStaticTrait::GetInstance()->callback_;
+}
+
+void ResurrectStaticSingleton() {
+}
+
+}  // namespace
+
+class SingletonTest : public testing::Test {
+ public:
+  SingletonTest() { }
+
+  virtual void SetUp() {
+    non_leak_called_ = false;
+    leaky_called_ = false;
+    static_called_ = false;
+  }
+
+ protected:
+  void VerifiesCallbacks() {
+    EXPECT_TRUE(non_leak_called_);
+    EXPECT_FALSE(leaky_called_);
+    EXPECT_TRUE(static_called_);
+    non_leak_called_ = false;
+    leaky_called_ = false;
+    static_called_ = false;
+  }
+
+  void VerifiesCallbacksNotCalled() {
+    EXPECT_FALSE(non_leak_called_);
+    EXPECT_FALSE(leaky_called_);
+    EXPECT_FALSE(static_called_);
+    non_leak_called_ = false;
+    leaky_called_ = false;
+    static_called_ = false;
+  }
+
+  static void CallbackNoLeak() {
+    non_leak_called_ = true;
+  }
+
+  static void CallbackLeak() {
+    leaky_called_ = true;
+  }
+
+  static void CallbackStatic() {
+    static_called_ = true;
+  }
+
+ private:
+  static bool non_leak_called_;
+  static bool leaky_called_;
+  static bool static_called_;
+};
+
+bool SingletonTest::non_leak_called_ = false;
+bool SingletonTest::leaky_called_ = false;
+bool SingletonTest::static_called_ = false;
+
+TEST_F(SingletonTest, Basic) {
+  int* singleton_int;
+  int* singleton_int_5;
+  CallbackFunc* leaky_singleton;
+  CallbackFunc* static_singleton;
+
+  {
+    base::ShadowingAtExitManager sem;
+    {
+      singleton_int = SingletonInt();
+    }
+    // Ensure POD type initialization.
+    EXPECT_EQ(*singleton_int, 0);
+    *singleton_int = 1;
+
+    EXPECT_EQ(singleton_int, SingletonInt());
+    EXPECT_EQ(*singleton_int, 1);
+
+    {
+      singleton_int_5 = SingletonInt5();
+    }
+    // Is default initialized to 5.
+    EXPECT_EQ(*singleton_int_5, 5);
+
+    SingletonNoLeak(&CallbackNoLeak);
+    SingletonLeak(&CallbackLeak);
+    SingletonStatic(&CallbackStatic);
+    static_singleton = GetStaticSingleton();
+    leaky_singleton = GetLeakySingleton();
+    EXPECT_TRUE(leaky_singleton);
+  }
+
+  // Verify that only the expected callback has been called.
+  VerifiesCallbacks();
+  // Delete the leaky singleton. It is interesting to note that Purify does
+  // *not* detect the leak when this call is commented out. :(
+  DeleteLeakySingleton();
+
+  // The static singleton can't be acquired post-atexit.
+  EXPECT_EQ(NULL, GetStaticSingleton());
+
+  {
+    base::ShadowingAtExitManager sem;
+    // Verifiy that the variables were reset.
+    {
+      singleton_int = SingletonInt();
+      EXPECT_EQ(*singleton_int, 0);
+    }
+    {
+      singleton_int_5 = SingletonInt5();
+      EXPECT_EQ(*singleton_int_5, 5);
+    }
+    {
+      // Resurrect the static singleton, and assert that it
+      // still points to the same (static) memory.
+      CallbackSingletonWithStaticTrait::Trait::Resurrect();
+      EXPECT_EQ(GetStaticSingleton(), static_singleton);
+    }
+  }
+  // The leaky singleton shouldn't leak since SingletonLeak has not been called.
+  VerifiesCallbacksNotCalled();
+}
diff --git a/base/memory/weak_ptr.cc b/base/memory/weak_ptr.cc
new file mode 100644
index 0000000..fb09219
--- /dev/null
+++ b/base/memory/weak_ptr.cc
@@ -0,0 +1,81 @@
+// 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) {
+}
+
+WeakReference::Flag::~Flag() {
+  if (handle_)
+    *handle_ = NULL;
+}
+
+void WeakReference::Flag::AddRef() const {
+  DCHECK(CalledOnValidThread());
+  RefCounted<Flag>::AddRef();
+}
+
+void WeakReference::Flag::Release() const {
+  DCHECK(CalledOnValidThread());
+  RefCounted<Flag>::Release();
+}
+
+void WeakReference::Flag::Invalidate() {
+  DCHECK(CalledOnValidThread());
+  handle_ = NULL;
+}
+
+bool WeakReference::Flag::IsValid() const {
+  DCHECK(CalledOnValidThread());
+  return handle_ != NULL;
+}
+
+WeakReference::WeakReference() {
+}
+
+WeakReference::WeakReference(Flag* flag) : flag_(flag) {
+}
+
+WeakReference::~WeakReference() {
+}
+
+bool WeakReference::is_valid() const {
+  return flag_ && flag_->IsValid();
+}
+
+WeakReferenceOwner::WeakReferenceOwner() : flag_(NULL) {
+}
+
+WeakReferenceOwner::~WeakReferenceOwner() {
+  Invalidate();
+}
+
+WeakReference WeakReferenceOwner::GetRef() const {
+  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
diff --git a/base/memory/weak_ptr.h b/base/memory/weak_ptr.h
new file mode 100644
index 0000000..edb9d93
--- /dev/null
+++ b/base/memory/weak_ptr.h
@@ -0,0 +1,246 @@
+// 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.
+
+// Weak pointers help in cases where you have many objects referring back to a
+// shared object and you wish for the lifetime of the shared object to not be
+// bound to the lifetime of the referrers.  In other words, this is useful when
+// reference counting is not a good fit.
+//
+// A common alternative to weak pointers is to have the shared object hold a
+// list of all referrers, and then when the shared object is destroyed, it
+// calls a method on the referrers to tell them to drop their references.  This
+// approach also requires the referrers to tell the shared object when they get
+// destroyed so that the shared object can remove the referrer from its list of
+// referrers.  Such a solution works, but it is a bit complex.
+//
+// EXAMPLE:
+//
+//  class Controller : public SupportsWeakPtr<Controller> {
+//   public:
+//    void SpawnWorker() { Worker::StartNew(AsWeakPtr()); }
+//    void WorkComplete(const Result& result) { ... }
+//  };
+//
+//  class Worker {
+//   public:
+//    static void StartNew(const WeakPtr<Controller>& controller) {
+//      Worker* worker = new Worker(controller);
+//      // Kick off asynchronous processing...
+//    }
+//   private:
+//    Worker(const WeakPtr<Controller>& controller)
+//        : controller_(controller) {}
+//    void DidCompleteAsynchronousProcessing(const Result& result) {
+//      if (controller_)
+//        controller_->WorkComplete(result);
+//    }
+//    WeakPtr<Controller> controller_;
+//  };
+//
+// Given the above classes, a consumer may allocate a Controller object, call
+// SpawnWorker several times, and then destroy the Controller object before all
+// of the workers have completed.  Because the Worker class only holds a weak
+// pointer to the Controller, we don't have to worry about the Worker
+// dereferencing the Controller back pointer after the Controller has been
+// destroyed.
+//
+// WARNING: weak pointers are not threadsafe!!!  You must only use a WeakPtr
+// instance on thread where it was created.
+
+#ifndef BASE_MEMORY_WEAK_PTR_H_
+#define BASE_MEMORY_WEAK_PTR_H_
+#pragma once
+
+#include "base/base_api.h"
+#include "base/logging.h"
+#include "base/memory/ref_counted.h"
+#include "base/threading/non_thread_safe.h"
+
+namespace base {
+
+namespace internal {
+// These classes are part of the WeakPtr implementation.
+// DO NOT USE THESE CLASSES DIRECTLY YOURSELF.
+
+class BASE_API WeakReference {
+ public:
+  class Flag : public RefCounted<Flag>, public base::NonThreadSafe {
+   public:
+    Flag(Flag** handle);
+    ~Flag();
+
+    void AddRef() const;
+    void Release() const;
+    void Invalidate();
+    bool IsValid() const;
+
+    void DetachFromThread() { base::NonThreadSafe::DetachFromThread(); }
+
+   private:
+    Flag** handle_;
+  };
+
+  WeakReference();
+  WeakReference(Flag* flag);
+  ~WeakReference();
+
+  bool is_valid() const;
+
+ private:
+  scoped_refptr<Flag> flag_;
+};
+
+class BASE_API WeakReferenceOwner {
+ public:
+  WeakReferenceOwner();
+  ~WeakReferenceOwner();
+
+  WeakReference GetRef() const;
+
+  bool HasRefs() const {
+    return flag_ != NULL;
+  }
+
+  void Invalidate();
+
+  // Indicates that this object will be used on another thread from now on.
+  void DetachFromThread() {
+    if (flag_) flag_->DetachFromThread();
+  }
+
+ private:
+  mutable WeakReference::Flag* flag_;
+};
+
+// This class simplifies the implementation of WeakPtr's type conversion
+// constructor by avoiding the need for a public accessor for ref_.  A
+// WeakPtr<T> cannot access the private members of WeakPtr<U>, so this
+// base class gives us a way to access ref_ in a protected fashion.
+class BASE_API WeakPtrBase {
+ public:
+  WeakPtrBase();
+  ~WeakPtrBase();
+
+ protected:
+  WeakPtrBase(const WeakReference& ref);
+
+  WeakReference ref_;
+};
+
+}  // namespace internal
+
+template <typename T> class SupportsWeakPtr;
+template <typename T> class WeakPtrFactory;
+
+// The WeakPtr class holds a weak reference to |T*|.
+//
+// This class is designed to be used like a normal pointer.  You should always
+// null-test an object of this class before using it or invoking a method that
+// may result in the underlying object being destroyed.
+//
+// EXAMPLE:
+//
+//   class Foo { ... };
+//   WeakPtr<Foo> foo;
+//   if (foo)
+//     foo->method();
+//
+template <typename T>
+class WeakPtr : public internal::WeakPtrBase {
+ public:
+  WeakPtr() : ptr_(NULL) {
+  }
+
+  // Allow conversion from U to T provided U "is a" T.
+  template <typename U>
+  WeakPtr(const WeakPtr<U>& other) : WeakPtrBase(other), ptr_(other.get()) {
+  }
+
+  T* get() const { return ref_.is_valid() ? ptr_ : NULL; }
+  operator T*() const { return get(); }
+
+  T* operator*() const {
+    DCHECK(get() != NULL);
+    return *get();
+  }
+  T* operator->() const {
+    DCHECK(get() != NULL);
+    return get();
+  }
+
+  void reset() {
+    ref_ = internal::WeakReference();
+    ptr_ = NULL;
+  }
+
+ private:
+  friend class SupportsWeakPtr<T>;
+  friend class WeakPtrFactory<T>;
+
+  WeakPtr(const internal::WeakReference& ref, T* ptr)
+      : WeakPtrBase(ref), ptr_(ptr) {
+  }
+
+  // This pointer is only valid when ref_.is_valid() is true.  Otherwise, its
+  // value is undefined (as opposed to NULL).
+  T* ptr_;
+};
+
+// A class may extend from SupportsWeakPtr to expose weak pointers to itself.
+// This is useful in cases where you want others to be able to get a weak
+// pointer to your class.  It also has the property that you don't need to
+// initialize it from your constructor.
+template <class T>
+class SupportsWeakPtr {
+ public:
+  SupportsWeakPtr() {}
+
+  WeakPtr<T> AsWeakPtr() {
+    return WeakPtr<T>(weak_reference_owner_.GetRef(), static_cast<T*>(this));
+  }
+
+  // Indicates that this object will be used on another thread from now on.
+  void DetachFromThread() {
+    weak_reference_owner_.DetachFromThread();
+  }
+
+ private:
+  internal::WeakReferenceOwner weak_reference_owner_;
+  DISALLOW_COPY_AND_ASSIGN(SupportsWeakPtr);
+};
+
+// A class may alternatively be composed of a WeakPtrFactory and thereby
+// control how it exposes weak pointers to itself.  This is helpful if you only
+// need weak pointers within the implementation of a class.  This class is also
+// useful when working with primitive types.  For example, you could have a
+// WeakPtrFactory<bool> that is used to pass around a weak reference to a bool.
+template <class T>
+class WeakPtrFactory {
+ public:
+  explicit WeakPtrFactory(T* ptr) : ptr_(ptr) {
+  }
+
+  WeakPtr<T> GetWeakPtr() {
+    return WeakPtr<T>(weak_reference_owner_.GetRef(), ptr_);
+  }
+
+  // Call this method to invalidate all existing weak pointers.
+  void InvalidateWeakPtrs() {
+    weak_reference_owner_.Invalidate();
+  }
+
+  // Call this method to determine if any weak pointers exist.
+  bool HasWeakPtrs() const {
+    return weak_reference_owner_.HasRefs();
+  }
+
+ private:
+  internal::WeakReferenceOwner weak_reference_owner_;
+  T* ptr_;
+  DISALLOW_IMPLICIT_CONSTRUCTORS(WeakPtrFactory);
+};
+
+}  // namespace base
+
+#endif  // BASE_MEMORY_WEAK_PTR_H_
diff --git a/base/memory/weak_ptr_unittest.cc b/base/memory/weak_ptr_unittest.cc
new file mode 100644
index 0000000..6c2a7e8
--- /dev/null
+++ b/base/memory/weak_ptr_unittest.cc
@@ -0,0 +1,137 @@
+// 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/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "base/message_loop.h"
+#include "base/threading/thread.h"
+
+namespace base {
+namespace {
+
+template <class T>
+class OffThreadObjectCreator {
+ public:
+  static T* NewObject() {
+    T* result;
+    {
+      Thread creator_thread("creator_thread");
+      creator_thread.Start();
+      creator_thread.message_loop()->PostTask(
+          FROM_HERE,
+          NewRunnableFunction(OffThreadObjectCreator::CreateObject, &result));
+    }
+    DCHECK(result);  // We synchronized on thread destruction above.
+    return result;
+  }
+ private:
+  static void CreateObject(T** result) {
+    *result = new T;
+  }
+};
+
+struct Base {};
+struct Derived : Base {};
+
+struct Producer : SupportsWeakPtr<Producer> {};
+struct Consumer { WeakPtr<Producer> producer; };
+
+}  // namespace
+
+TEST(WeakPtrTest, Basic) {
+  int data;
+  WeakPtrFactory<int> factory(&data);
+  WeakPtr<int> ptr = factory.GetWeakPtr();
+  EXPECT_EQ(&data, ptr.get());
+}
+
+TEST(WeakPtrTest, Comparison) {
+  int data;
+  WeakPtrFactory<int> factory(&data);
+  WeakPtr<int> ptr = factory.GetWeakPtr();
+  WeakPtr<int> ptr2 = ptr;
+  EXPECT_TRUE(ptr == ptr2);
+}
+
+TEST(WeakPtrTest, OutOfScope) {
+  WeakPtr<int> ptr;
+  EXPECT_TRUE(ptr.get() == NULL);
+  {
+    int data;
+    WeakPtrFactory<int> factory(&data);
+    ptr = factory.GetWeakPtr();
+  }
+  EXPECT_TRUE(ptr.get() == NULL);
+}
+
+TEST(WeakPtrTest, Multiple) {
+  WeakPtr<int> a, b;
+  {
+    int data;
+    WeakPtrFactory<int> factory(&data);
+    a = factory.GetWeakPtr();
+    b = factory.GetWeakPtr();
+    EXPECT_EQ(&data, a.get());
+    EXPECT_EQ(&data, b.get());
+  }
+  EXPECT_TRUE(a.get() == NULL);
+  EXPECT_TRUE(b.get() == NULL);
+}
+
+TEST(WeakPtrTest, UpCast) {
+  Derived data;
+  WeakPtrFactory<Derived> factory(&data);
+  WeakPtr<Base> ptr = factory.GetWeakPtr();
+  ptr = factory.GetWeakPtr();
+  EXPECT_EQ(ptr.get(), &data);
+}
+
+TEST(WeakPtrTest, SupportsWeakPtr) {
+  Producer f;
+  WeakPtr<Producer> ptr = f.AsWeakPtr();
+  EXPECT_EQ(&f, ptr.get());
+}
+
+TEST(WeakPtrTest, InvalidateWeakPtrs) {
+  int data;
+  WeakPtrFactory<int> factory(&data);
+  WeakPtr<int> ptr = factory.GetWeakPtr();
+  EXPECT_EQ(&data, ptr.get());
+  EXPECT_TRUE(factory.HasWeakPtrs());
+  factory.InvalidateWeakPtrs();
+  EXPECT_TRUE(ptr.get() == NULL);
+  EXPECT_FALSE(factory.HasWeakPtrs());
+}
+
+TEST(WeakPtrTest, HasWeakPtrs) {
+  int data;
+  WeakPtrFactory<int> factory(&data);
+  {
+    WeakPtr<int> ptr = factory.GetWeakPtr();
+    EXPECT_TRUE(factory.HasWeakPtrs());
+  }
+  EXPECT_FALSE(factory.HasWeakPtrs());
+}
+
+TEST(WeakPtrTest, SingleThreaded1) {
+  // Test that it is OK to create a class that supports weak references on one
+  // thread, but use it on another.  This tests that we do not trip runtime
+  // checks that ensure that a weak reference is not used by multiple threads.
+  scoped_ptr<Producer> producer(OffThreadObjectCreator<Producer>::NewObject());
+  WeakPtr<Producer> weak_producer = producer->AsWeakPtr();
+  EXPECT_EQ(producer.get(), weak_producer.get());
+}
+
+TEST(WeakPtrTest, SingleThreaded2) {
+  // Test that it is OK to create a class that has a WeakPtr member on one
+  // thread, but use it on another.  This tests that we do not trip runtime
+  // checks that ensure that a weak reference is not used by multiple threads.
+  scoped_ptr<Consumer> consumer(OffThreadObjectCreator<Consumer>::NewObject());
+  Producer producer;
+  consumer->producer = producer.AsWeakPtr();
+  EXPECT_EQ(&producer, consumer->producer.get());
+}
+
+}  // namespace base