Move paint aggregator and the completion callback factory.

ppapi/utility/completion_callback_factory.h

Index: ppapi/utility/completion_callback_factory.h
diff --git a/ppapi/cpp/completion_callback.h b/ppapi/utility/completion_callback_factory.h
similarity index 74%
copy from ppapi/cpp/completion_callback.h
copy to ppapi/utility/completion_callback_factory.h
index 2e5f38b9e9c11df90065c744f4ffe86edf03cfbb..b656024097c77ff338cbace98cc2703cd38ee4fe 100644
--- a/ppapi/cpp/completion_callback.h
+++ b/ppapi/utility/completion_callback_factory.h
@@ -1,710 +1,564 @@
-// 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 PPAPI_CPP_COMPLETION_CALLBACK_H_
-#define PPAPI_CPP_COMPLETION_CALLBACK_H_
-
-#include "ppapi/c/pp_completion_callback.h"
-#include "ppapi/c/pp_errors.h"
-#include "ppapi/cpp/logging.h"
-#include "ppapi/cpp/non_thread_safe_ref_count.h"
-
-/// @file
-/// This file defines the API to create and run a callback.
-namespace pp {
-
-/// This API enables you to implement and receive callbacks when
-/// Pepper operations complete asynchronously.
-class CompletionCallback {
- public:
-  /// The default constructor will create a blocking
-  /// <code>CompletionCallback</code> that can be passed to a method to
-  /// indicate that the calling thread should be blocked until the asynchronous
-  /// operation corresponding to the method completes.
-  ///
-  /// <strong>Note:</strong> Blocking completion callbacks are only allowed from
-  /// from background threads.
-  CompletionCallback() {
-    cc_ = PP_BlockUntilComplete();
-  }
-
-  /// A constructor for creating a <code>CompletionCallback</code>.
-  ///
-  /// @param[in] func The function to be called on completion.
-  /// @param[in] user_data The user data to be passed to the callback function.
-  /// This is optional and is typically used to help track state in case of
-  /// multiple pending callbacks.
-  CompletionCallback(PP_CompletionCallback_Func func, void* user_data) {
-    cc_ = PP_MakeCompletionCallback(func, user_data);
-  }
-
-  /// A constructor for creating a <code>CompletionCallback</code> with
-  /// specified flags.
-  ///
-  /// @param[in] func The function to be called on completion.
-  /// @param[in] user_data The user data to be passed to the callback function.
-  /// This is optional and is typically used to help track state in case of
-  /// multiple pending callbacks.
-  /// @param[in] flags Bit field combination of
-  /// <code>PP_CompletionCallback_Flag</code> flags used to control how
-  /// non-NULL callbacks are scheduled by asynchronous methods.
-  CompletionCallback(PP_CompletionCallback_Func func, void* user_data,
-                     int32_t flags) {
-    cc_ = PP_MakeCompletionCallback(func, user_data);
-    cc_.flags = flags;
-  }
-
-  /// The set_flags() function is used to set the flags used to control
-  /// how non-NULL callbacks are scheduled by asynchronous methods.
-  ///
-  /// @param[in] flags Bit field combination of
-  /// <code>PP_CompletionCallback_Flag</code> flags used to control how
-  /// non-NULL callbacks are scheduled by asynchronous methods.
-  void set_flags(int32_t flags) { cc_.flags = flags; }
-
-  /// Run() is used to run the <code>CompletionCallback</code>.
-  /// Normally, the system runs a <code>CompletionCallback</code> after an
-  /// asynchronous operation completes, but programs may wish to run the
-  /// <code>CompletionCallback</code> manually in order to reuse the same code
-  /// paths.
-  ///
-  /// @param[in] result The result of the operation to be passed to the
-  /// callback function. Non-positive values correspond to the error codes
-  /// from <code>pp_errors.h</code> (excluding
-  /// <code>PP_OK_COMPLETIONPENDING</code>). Positive values indicate
-  /// additional information such as bytes read.
-  void Run(int32_t result) {
-    PP_DCHECK(cc_.func);
-    PP_RunCompletionCallback(&cc_, result);
-  }
-
-  /// IsOptional() is used to determine the setting of the
-  /// <code>PP_COMPLETIONCALLBACK_FLAG_OPTIONAL</code> flag. This flag allows
-  /// any method taking such callback to complete synchronously
-  /// and not call the callback if the operation would not block. This is useful
-  /// when performance is an issue, and the operation bandwidth should not be
-  /// limited to the processing speed of the message loop.
-  ///
-  /// On synchronous method completion, the completion result will be returned
-  /// by the method itself. Otherwise, the method will return
-  /// PP_OK_COMPLETIONPENDING, and the callback will be invoked asynchronously
-  /// on the main thread of Pepper execution.
-  ///
-  /// @return true if this callback is optional, otherwise false.
-  bool IsOptional() const {
-    return (cc_.func == NULL ||
-            (cc_.flags & PP_COMPLETIONCALLBACK_FLAG_OPTIONAL) != 0);
-  }
-
-  /// The pp_completion_callback() function returns the underlying
-  /// <code>PP_CompletionCallback</code>
-  ///
-  /// @return A <code>PP_CompletionCallback</code>.
-  const PP_CompletionCallback& pp_completion_callback() const { return cc_; }
-
-  /// The flags() function returns flags used to control how non-NULL callbacks
-  /// are scheduled by asynchronous methods.
-  ///
-  /// @return An int32_t containing a bit field combination of
-  /// <code>PP_CompletionCallback_Flag</code> flags.
-  int32_t flags() const { return cc_.flags; }
-
-  /// MayForce() is used when implementing functions taking callbacks.
-  /// If the callback is required and <code>result</code> indicates that it has
-  /// not been scheduled, it will be forced on the main thread.
-  ///
-  /// <strong>Example:</strong>
-  ///
-  /// @code
-  ///
-  /// int32_t OpenURL(pp::URLLoader* loader,
-  ///                 pp::URLRequestInfo* url_request_info,
-  ///                 const CompletionCallback& cc) {
-  ///   if (loader == NULL || url_request_info == NULL)
-  ///     return cc.MayForce(PP_ERROR_BADRESOURCE);
-  ///   return loader->Open(*loader, *url_request_info, cc);
-  /// }
-  ///
-  /// @endcode
-  ///
-  /// @param[in] result PP_OK_COMPLETIONPENDING or the result of the completed
-  /// operation to be passed to the callback function. PP_OK_COMPLETIONPENDING
-  /// indicates that the callback has already been scheduled. Other
-  /// non-positive values correspond to error codes from
-  /// <code>pp_errors.h</code>. Positive values indicate additional information
-  /// such as bytes read.
-  ///
-  /// @return <code>PP_OK_COMPLETIONPENDING</code> if the callback has been
-  /// forced, result parameter otherwise.
-  int32_t MayForce(int32_t result) const {
-    if (result == PP_OK_COMPLETIONPENDING || IsOptional())
-      return result;
-    Module::Get()->core()->CallOnMainThread(0, *this, result);
-    return PP_OK_COMPLETIONPENDING;
-  }
-
- protected:
-  PP_CompletionCallback cc_;
-};
-
-/// BlockUntilComplete() is used in place of an actual completion callback
-/// to request blocking behavior. If specified, the calling thread will block
-/// until the function completes. Blocking completion callbacks are only
-/// allowed from background threads.
-///
-/// @return A <code>CompletionCallback</code> corresponding to a NULL callback.
-CompletionCallback BlockUntilComplete();
-
-/// CompletionCallbackFactory<T> may be used to create CompletionCallback
-/// objects that are bound to member functions.
-///
-/// If a factory is destroyed, then any pending callbacks will be cancelled
-/// preventing any bound member functions from being called.  The CancelAll()
-/// method allows pending callbacks to be cancelled without destroying the
-/// factory.
-///
-/// <strong>Note: </strong><code>CompletionCallbackFactory<T></code> isn't
-/// thread safe, but you can make it more thread-friendly by passing a
-/// thread-safe refcounting class as the second template element. However, it
-/// only guarantees safety for creating a callback from another thread, the
-/// callback itself needs to execute on the same thread as the thread that
-/// creates/destroys the factory. With this restriction, it is safe to create
-/// the <code>CompletionCallbackFactory</code> on the main thread, create
-/// callbacks from any thread and pass them to CallOnMainThread().
-///
-/// <strong>Example: </strong>
-///
-/// @code
-///
-///   class MyHandler {
-///    public:
-///     // If an compiler warns on following using |this| in the initializer
-///     // list, use PP_ALLOW_THIS_IN_INITIALIZER_LIST macro.
-///     MyHandler() : factory_(this), offset_(0) {
-///     }
-///
-///    void ProcessFile(const FileRef& file) {
-///       CompletionCallback cc = factory_.NewRequiredCallback(
-///           &MyHandler::DidOpen);
-///       int32_t rv = fio_.Open(file, PP_FileOpenFlag_Read, cc);
-///       CHECK(rv == PP_OK_COMPLETIONPENDING);
-///     }
-///
-///    private:
-///     CompletionCallback NewCallback() {
-///       return factory_.NewCallback(&MyHandler::DidCompleteIO);
-///     }
-///
-///     void DidOpen(int32_t result) {
-///       if (result == PP_OK) {
-///         // The file is open, and we can begin reading.
-///         offset_ = 0;
-///         ReadMore();
-///       } else {
-///         // Failed to open the file with error given by 'result'.
-///       }
-///     }
-///
-///     void DidRead(int32_t result) {
-///       if (result > 0) {
-///         // buf_ now contains 'result' number of bytes from the file.
-///         ProcessBytes(buf_, result);
-///         offset_ += result;
-///         ReadMore();
-///       } else {
-///         // Done reading (possibly with an error given by 'result').
-///       }
-///     }
-///
-///     void ReadMore() {
-///       CompletionCallback cc =
-///           factory_.NewOptionalCallback(&MyHandler::DidRead);
-///       int32_t rv = fio_.Read(offset_, buf_, sizeof(buf_),
-///                              cc.pp_completion_callback());
-///       if (rv != PP_OK_COMPLETIONPENDING)
-///         cc.Run(rv);
-///     }
-///
-///     void ProcessBytes(const char* bytes, int32_t length) {
-///       // Do work ...
-///     }
-///
-///     pp::CompletionCallbackFactory<MyHandler> factory_;
-///     pp::FileIO fio_;
-///     char buf_[4096];
-///     int64_t offset_;
-///   };
-///
-/// @endcode
-///
-template <typename T, typename RefCount = NonThreadSafeRefCount>
-class CompletionCallbackFactory {
- public:
-
-  /// This constructor creates a <code>CompletionCallbackFactory</code>
-  /// bound to an object. If the constructor is called without an argument,
-  /// the default value of <code>NULL</code> is used. The user then must call
-  /// Initialize() to initialize the object.
-  ///
-  /// param[in] object Optional parameter. An object whose member functions
-  /// are to be bound to CompletionCallbacks created by this
-  /// <code>CompletionCallbackFactory</code>. The default value of this
-  /// parameter is <code>NULL</code>.
-  explicit CompletionCallbackFactory(T* object = NULL)
-      : object_(object) {
-    InitBackPointer();
-  }
-
-  /// Destructor.
-  ~CompletionCallbackFactory() {
-    ResetBackPointer();
-  }
-
-  /// CancelAll() cancels all <code>CompletionCallbacks</code> allocated from
-  /// this factory.
-  void CancelAll() {
-    ResetBackPointer();
-    InitBackPointer();
-  }
-  /// Initialize() binds the <code>CallbackFactory</code> to a particular
-  /// object. Use this when the object is not available at
-  /// <code>CallbackFactory</code> creation, and the <code>NULL</code> default
-  /// is passed to the constructor. The object may only be initialized once,
-  /// either by the constructor, or by a call to Initialize().
-  ///
-  /// @param[in] object The object whose member functions are to be bound to
-  /// the <code>CompletionCallback</code> created by this
-  /// <code>CompletionCallbackFactory</code>.
-  void Initialize(T* object) {
-    PP_DCHECK(object);
-    PP_DCHECK(!object_);  // May only initialize once!
-    object_ = object;
-  }
-
-  /// GetObject() returns the object that was passed at initialization to
-  /// Intialize().
-  ///
-  /// @return the object passed to the constructor or Intialize().
-  T* GetObject() {
-    return object_;
-  }
-
-  /// NewCallback allocates a new, single-use <code>CompletionCallback</code>.
-  /// The <code>CompletionCallback</code> must be run in order for the memory
-  /// allocated by the methods to be freed.
-  /// NewCallback() is equivalent to NewRequiredCallback() below.
-  ///
-  /// @param[in] method The method to be invoked upon completion of the
-  /// operation.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method>
-  CompletionCallback NewCallback(Method method) {
-    PP_DCHECK(object_);
-    return NewCallbackHelper(Dispatcher0<Method>(method));
-  }
-
-  /// NewRequiredCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code> that will always run. The
-  /// <code>CompletionCallback</code> must be run in order for the memory
-  /// allocated by the methods to be freed.
-  ///
-  /// @param[in] method The method to be invoked upon completion of the
-  /// operation.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method>
-  CompletionCallback NewRequiredCallback(Method method) {
-    CompletionCallback cc = NewCallback(method);
-    cc.set_flags(cc.flags() & ~PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
-    return cc;
-  }
-
-  /// NewOptionalCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code> that might not run if the method
-  /// taking it can complete synchronously. Thus, if after passing the
-  /// CompletionCallback to a Pepper method, the method does not return
-  /// PP_OK_COMPLETIONPENDING, then you should manually call the
-  /// CompletionCallback's Run method, or memory will be leaked.
-  ///
-  /// @param[in] method The method to be invoked upon completion of the
-  /// operation.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method>
-  CompletionCallback NewOptionalCallback(Method method) {
-    CompletionCallback cc = NewCallback(method);
-    cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
-    return cc;
-  }
-
-  /// NewCallback() allocates a new, single-use <code>CompletionCallback</code>.
-  /// The <code>CompletionCallback</code> must be run in order for the memory
-  /// allocated by the methods to be freed.
-  /// NewCallback() is equivalent to NewRequiredCallback() below.
-  ///
-  /// @param[in] method The method to be invoked upon completion of the
-  /// operation. Method should be of type:
-  /// <code>void (T::*)(int32_t result, const A& a)</code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A>
-  CompletionCallback NewCallback(Method method, const A& a) {
-    PP_DCHECK(object_);
-    return NewCallbackHelper(Dispatcher1<Method, A>(method, a));
-  }
-
-  /// NewRequiredCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code> that will always run. The
-  /// <code>CompletionCallback</code> must be run in order for the memory
-  /// allocated by the methods to be freed.
-  ///
-  /// @param[in] method The method to be invoked upon completion of the
-  /// operation. Method should be of type:
-  /// <code>void (T::*)(int32_t result, const A& a)</code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A>
-  CompletionCallback NewRequiredCallback(Method method, const A& a) {
-    CompletionCallback cc = NewCallback(method, a);
-    cc.set_flags(cc.flags() & ~PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
-    return cc;
-  }
-
-  /// NewOptionalCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code> that might not run if the method
-  /// taking it can complete synchronously. Thus, if after passing the
-  /// CompletionCallback to a Pepper method, the method does not return
-  /// PP_OK_COMPLETIONPENDING, then you should manually call the
-  /// CompletionCallback's Run method, or memory will be leaked.
-  ///
-  /// @param[in] method The method to be invoked upon completion of the
-  /// operation. Method should be of type:
-  /// <code>void (T::*)(int32_t result, const A& a)</code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A>
-  CompletionCallback NewOptionalCallback(Method method, const A& a) {
-    CompletionCallback cc = NewCallback(method, a);
-    cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
-    return cc;
-  }
-
-  /// NewCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code>.
-  /// The <code>CompletionCallback</code> must be run in order for the memory
-  /// allocated by the methods to be freed.
-  /// NewCallback() is equivalent to NewRequiredCallback() below.
-  ///
-  /// @param method The method taking the callback. Method should be of type:
-  /// <code>void (T::*)(int32_t result, const A& a, const B& b)</code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] b Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A, typename B>
-  CompletionCallback NewCallback(Method method, const A& a, const B& b) {
-    PP_DCHECK(object_);
-    return NewCallbackHelper(Dispatcher2<Method, A, B>(method, a, b));
-  }
-
-  /// NewRequiredCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code> that will always run. The
-  /// <code>CompletionCallback</code> must be run in order for the memory
-  /// allocated by the methods to be freed.
-  ///
-  /// @param method The method taking the callback. Method should be of type:
-  /// <code>void (T::*)(int32_t result, const A& a, const B& b)</code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] b Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A, typename B>
-  CompletionCallback NewRequiredCallback(Method method, const A& a,
-                                         const B& b) {
-    CompletionCallback cc = NewCallback(method, a, b);
-    cc.set_flags(cc.flags() & ~PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
-    return cc;
-  }
-
-  /// NewOptionalCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code> that might not run if the method
-  /// taking it can complete synchronously. Thus, if after passing the
-  /// CompletionCallback to a Pepper method, the method does not return
-  /// PP_OK_COMPLETIONPENDING, then you should manually call the
-  /// CompletionCallback's Run method, or memory will be leaked.
-  ///
-  /// @param[in] method The method taking the callback. Method should be of
-  /// type:
-  /// <code>void (T::*)(int32_t result, const A& a, const B& b)</code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] b Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A, typename B>
-  CompletionCallback NewOptionalCallback(Method method, const A& a,
-                                         const B& b) {
-    CompletionCallback cc = NewCallback(method, a, b);
-    cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
-    return cc;
-  }
-
-  /// NewCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code>.
-  /// The <code>CompletionCallback</code> must be run in order for the memory
-  /// allocated by the methods to be freed.
-  /// NewCallback() is equivalent to NewRequiredCallback() below.
-  ///
-  /// @param method The method taking the callback. Method should be of type:
-  /// <code>
-  /// void (T::*)(int32_t result, const A& a, const B& b, const C& c)
-  /// </code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] b Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] c Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A, typename B, typename C>
-  CompletionCallback NewCallback(Method method, const A& a, const B& b,
-                                 const C& c) {
-    PP_DCHECK(object_);
-    return NewCallbackHelper(Dispatcher3<Method, A, B, C>(method, a, b, c));
-  }
-
-  /// NewRequiredCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code> that will always run. The
-  /// <code>CompletionCallback</code> must be run in order for the memory
-  /// allocated by the methods to be freed.
-  ///
-  /// @param method The method taking the callback. Method should be of type:
-  /// <code>
-  /// void (T::*)(int32_t result, const A& a, const B& b, const C& c)
-  /// </code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] b Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] c Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A, typename B, typename C>
-  CompletionCallback NewRequiredCallback(Method method, const A& a,
-                                         const B& b, const C& c) {
-    CompletionCallback cc = NewCallback(method, a, b, c);
-    cc.set_flags(cc.flags() & ~PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
-    return cc;
-  }
-
-  /// NewOptionalCallback() allocates a new, single-use
-  /// <code>CompletionCallback</code> that might not run if the method
-  /// taking it can complete synchronously. Thus, if after passing the
-  /// CompletionCallback to a Pepper method, the method does not return
-  /// PP_OK_COMPLETIONPENDING, then you should manually call the
-  /// CompletionCallback's Run method, or memory will be leaked.
-  ///
-  /// @param[in] method The method taking the callback. Method should be of
-  /// type:
-  /// <code>
-  /// void (T::*)(int32_t result, const A& a, const B& b, const C& c)
-  /// </code>
-  ///
-  /// @param[in] a Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] b Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @param[in] c Passed to <code>method</code> when the completion callback
-  /// runs.
-  ///
-  /// @return A <code>CompletionCallback</code>.
-  template <typename Method, typename A, typename B, typename C>
-  CompletionCallback NewOptionalCallback(Method method, const A& a,
-                                         const B& b, const C& c) {
-    CompletionCallback cc = NewCallback(method, a, b, c);
-    cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
-    return cc;
-  }
-
- private:
-  class BackPointer {
-   public:
-    typedef CompletionCallbackFactory<T, RefCount> FactoryType;
-
-    BackPointer(FactoryType* factory)
-        : factory_(factory) {
-    }
-
-    void AddRef() {
-      ref_.AddRef();
-    }
-
-    void Release() {
-      if (ref_.Release() == 0)
-        delete this;
-    }
-
-    void DropFactory() {
-      factory_ = NULL;
-    }
-
-    T* GetObject() {
-      return factory_ ? factory_->GetObject() : NULL;
-    }
-
-   private:
-    RefCount ref_;
-    FactoryType* factory_;
-  };
-
-  template <typename Dispatcher>
-  class CallbackData {
-   public:
-    CallbackData(BackPointer* back_pointer, const Dispatcher& dispatcher)
-        : back_pointer_(back_pointer),
-          dispatcher_(dispatcher) {
-      back_pointer_->AddRef();
-    }
-
-    ~CallbackData() {
-      back_pointer_->Release();
-    }
-
-    static void Thunk(void* user_data, int32_t result) {
-      Self* self = static_cast<Self*>(user_data);
-      T* object = self->back_pointer_->GetObject();
-      if (object)
-        self->dispatcher_(object, result);
-      delete self;
-    }
-
-   private:
-    typedef CallbackData<Dispatcher> Self;
-    BackPointer* back_pointer_;
-    Dispatcher dispatcher_;
-  };
-
-  template <typename Method>
-  class Dispatcher0 {
-   public:
-    Dispatcher0(Method method) : method_(method) {
-    }
-    void operator()(T* object, int32_t result) {
-      (object->*method_)(result);
-    }
-   private:
-    Method method_;
-  };
-
-  template <typename Method, typename A>
-  class Dispatcher1 {
-   public:
-    Dispatcher1(Method method, const A& a)
-        : method_(method),
-          a_(a) {
-    }
-    void operator()(T* object, int32_t result) {
-      (object->*method_)(result, a_);
-    }
-   private:
-    Method method_;
-    A a_;
-  };
-
-  template <typename Method, typename A, typename B>
-  class Dispatcher2 {
-   public:
-    Dispatcher2(Method method, const A& a, const B& b)
-        : method_(method),
-          a_(a),
-          b_(b) {
-    }
-    void operator()(T* object, int32_t result) {
-      (object->*method_)(result, a_, b_);
-    }
-   private:
-    Method method_;
-    A a_;
-    B b_;
-  };
-
-  template <typename Method, typename A, typename B, typename C>
-  class Dispatcher3 {
-   public:
-    Dispatcher3(Method method, const A& a, const B& b, const C& c)
-        : method_(method),
-          a_(a),
-          b_(b),
-          c_(c) {
-    }
-    void operator()(T* object, int32_t result) {
-      (object->*method_)(result, a_, b_, c_);
-    }
-   private:
-    Method method_;
-    A a_;
-    B b_;
-    C c_;
-  };
-
-  void InitBackPointer() {
-    back_pointer_ = new BackPointer(this);
-    back_pointer_->AddRef();
-  }
-
-  void ResetBackPointer() {
-    back_pointer_->DropFactory();
-    back_pointer_->Release();
-  }
-
-  template <typename Dispatcher>
-  CompletionCallback NewCallbackHelper(const Dispatcher& dispatcher) {
-    PP_DCHECK(object_);  // Expects a non-null object!
-    return CompletionCallback(
-        &CallbackData<Dispatcher>::Thunk,
-        new CallbackData<Dispatcher>(back_pointer_, dispatcher));
-  }
-
-  // Disallowed:
-  CompletionCallbackFactory(const CompletionCallbackFactory&);
-  CompletionCallbackFactory& operator=(const CompletionCallbackFactory&);
-
-  T* object_;
-  BackPointer* back_pointer_;
-};
-
-}  // namespace pp
-
-#endif  // PPAPI_CPP_COMPLETION_CALLBACK_H_
+// 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 PPAPI_UTILITY_COMPLETION_CALLBACK_FACTORY_H_
+#define PPAPI_UTILITY_COMPLETION_CALLBACK_FACTORY_H_
+
+#include "ppapi/cpp/completion_callback.h"
+#include "ppapi/utility/non_thread_safe_ref_count.h"
+
+namespace pp {
+
+/// CompletionCallbackFactory<T> may be used to create CompletionCallback
+/// objects that are bound to member functions.
+///
+/// If a factory is destroyed, then any pending callbacks will be cancelled
+/// preventing any bound member functions from being called.  The CancelAll()
+/// method allows pending callbacks to be cancelled without destroying the
+/// factory.
+///
+/// <strong>Note: </strong><code>CompletionCallbackFactory<T></code> isn't
+/// thread safe, but you can make it more thread-friendly by passing a
+/// thread-safe refcounting class as the second template element. However, it
+/// only guarantees safety for creating a callback from another thread, the
+/// callback itself needs to execute on the same thread as the thread that
+/// creates/destroys the factory. With this restriction, it is safe to create
+/// the <code>CompletionCallbackFactory</code> on the main thread, create
+/// callbacks from any thread and pass them to CallOnMainThread().
+///
+/// <strong>Example: </strong>
+///
+/// @code
+///
+///   class MyHandler {
+///    public:
+///     // If an compiler warns on following using |this| in the initializer
+///     // list, use PP_ALLOW_THIS_IN_INITIALIZER_LIST macro.
+///     MyHandler() : factory_(this), offset_(0) {
+///     }
+///
+///    void ProcessFile(const FileRef& file) {
+///       CompletionCallback cc = factory_.NewRequiredCallback(
+///           &MyHandler::DidOpen);
+///       int32_t rv = fio_.Open(file, PP_FileOpenFlag_Read, cc);
+///       CHECK(rv == PP_OK_COMPLETIONPENDING);
+///     }
+///
+///    private:
+///     CompletionCallback NewCallback() {
+///       return factory_.NewCallback(&MyHandler::DidCompleteIO);
+///     }
+///
+///     void DidOpen(int32_t result) {
+///       if (result == PP_OK) {
+///         // The file is open, and we can begin reading.
+///         offset_ = 0;
+///         ReadMore();
+///       } else {
+///         // Failed to open the file with error given by 'result'.
+///       }
+///     }
+///
+///     void DidRead(int32_t result) {
+///       if (result > 0) {
+///         // buf_ now contains 'result' number of bytes from the file.
+///         ProcessBytes(buf_, result);
+///         offset_ += result;
+///         ReadMore();
+///       } else {
+///         // Done reading (possibly with an error given by 'result').
+///       }
+///     }
+///
+///     void ReadMore() {
+///       CompletionCallback cc =
+///           factory_.NewOptionalCallback(&MyHandler::DidRead);
+///       int32_t rv = fio_.Read(offset_, buf_, sizeof(buf_),
+///                              cc.pp_completion_callback());
+///       if (rv != PP_OK_COMPLETIONPENDING)
+///         cc.Run(rv);
+///     }
+///
+///     void ProcessBytes(const char* bytes, int32_t length) {
+///       // Do work ...
+///     }
+///
+///     pp::CompletionCallbackFactory<MyHandler> factory_;
+///     pp::FileIO fio_;
+///     char buf_[4096];
+///     int64_t offset_;
+///   };
+///
+/// @endcode
+///
+template <typename T, typename RefCount = NonThreadSafeRefCount>
+class CompletionCallbackFactory {
+ public:
+
+  /// This constructor creates a <code>CompletionCallbackFactory</code>
+  /// bound to an object. If the constructor is called without an argument,
+  /// the default value of <code>NULL</code> is used. The user then must call
+  /// Initialize() to initialize the object.
+  ///
+  /// param[in] object Optional parameter. An object whose member functions
+  /// are to be bound to CompletionCallbacks created by this
+  /// <code>CompletionCallbackFactory</code>. The default value of this
+  /// parameter is <code>NULL</code>.
+  explicit CompletionCallbackFactory(T* object = NULL)
+      : object_(object) {
+    InitBackPointer();
+  }
+
+  /// Destructor.
+  ~CompletionCallbackFactory() {
+    ResetBackPointer();
+  }
+
+  /// CancelAll() cancels all <code>CompletionCallbacks</code> allocated from
+  /// this factory.
+  void CancelAll() {
+    ResetBackPointer();
+    InitBackPointer();
+  }
+  /// Initialize() binds the <code>CallbackFactory</code> to a particular
+  /// object. Use this when the object is not available at
+  /// <code>CallbackFactory</code> creation, and the <code>NULL</code> default
+  /// is passed to the constructor. The object may only be initialized once,
+  /// either by the constructor, or by a call to Initialize().
+  ///
+  /// @param[in] object The object whose member functions are to be bound to
+  /// the <code>CompletionCallback</code> created by this
+  /// <code>CompletionCallbackFactory</code>.
+  void Initialize(T* object) {
+    PP_DCHECK(object);
+    PP_DCHECK(!object_);  // May only initialize once!
+    object_ = object;
+  }
+
+  /// GetObject() returns the object that was passed at initialization to
+  /// Intialize().
+  ///
+  /// @return the object passed to the constructor or Intialize().
+  T* GetObject() {
+    return object_;
+  }
+
+  /// NewCallback allocates a new, single-use <code>CompletionCallback</code>.
+  /// The <code>CompletionCallback</code> must be run in order for the memory
+  /// allocated by the methods to be freed.
+  /// NewCallback() is equivalent to NewRequiredCallback() below.
+  ///
+  /// @param[in] method The method to be invoked upon completion of the
+  /// operation.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method>
+  CompletionCallback NewCallback(Method method) {
+    PP_DCHECK(object_);
+    return NewCallbackHelper(Dispatcher0<Method>(method));
+  }
+
+  /// NewRequiredCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code> that will always run. The
+  /// <code>CompletionCallback</code> must be run in order for the memory
+  /// allocated by the methods to be freed.
+  ///
+  /// @param[in] method The method to be invoked upon completion of the
+  /// operation.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method>
+  CompletionCallback NewRequiredCallback(Method method) {
+    CompletionCallback cc = NewCallback(method);
+    cc.set_flags(cc.flags() & ~PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+    return cc;
+  }
+
+  /// NewOptionalCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code> that might not run if the method
+  /// taking it can complete synchronously. Thus, if after passing the
+  /// CompletionCallback to a Pepper method, the method does not return
+  /// PP_OK_COMPLETIONPENDING, then you should manually call the
+  /// CompletionCallback's Run method, or memory will be leaked.
+  ///
+  /// @param[in] method The method to be invoked upon completion of the
+  /// operation.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method>
+  CompletionCallback NewOptionalCallback(Method method) {
+    CompletionCallback cc = NewCallback(method);
+    cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+    return cc;
+  }
+
+  /// NewCallback() allocates a new, single-use <code>CompletionCallback</code>.
+  /// The <code>CompletionCallback</code> must be run in order for the memory
+  /// allocated by the methods to be freed.
+  /// NewCallback() is equivalent to NewRequiredCallback() below.
+  ///
+  /// @param[in] method The method to be invoked upon completion of the
+  /// operation. Method should be of type:
+  /// <code>void (T::*)(int32_t result, const A& a)</code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A>
+  CompletionCallback NewCallback(Method method, const A& a) {
+    PP_DCHECK(object_);
+    return NewCallbackHelper(Dispatcher1<Method, A>(method, a));
+  }
+
+  /// NewRequiredCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code> that will always run. The
+  /// <code>CompletionCallback</code> must be run in order for the memory
+  /// allocated by the methods to be freed.
+  ///
+  /// @param[in] method The method to be invoked upon completion of the
+  /// operation. Method should be of type:
+  /// <code>void (T::*)(int32_t result, const A& a)</code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A>
+  CompletionCallback NewRequiredCallback(Method method, const A& a) {
+    CompletionCallback cc = NewCallback(method, a);
+    cc.set_flags(cc.flags() & ~PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+    return cc;
+  }
+
+  /// NewOptionalCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code> that might not run if the method
+  /// taking it can complete synchronously. Thus, if after passing the
+  /// CompletionCallback to a Pepper method, the method does not return
+  /// PP_OK_COMPLETIONPENDING, then you should manually call the
+  /// CompletionCallback's Run method, or memory will be leaked.
+  ///
+  /// @param[in] method The method to be invoked upon completion of the
+  /// operation. Method should be of type:
+  /// <code>void (T::*)(int32_t result, const A& a)</code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A>
+  CompletionCallback NewOptionalCallback(Method method, const A& a) {
+    CompletionCallback cc = NewCallback(method, a);
+    cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+    return cc;
+  }
+
+  /// NewCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code>.
+  /// The <code>CompletionCallback</code> must be run in order for the memory
+  /// allocated by the methods to be freed.
+  /// NewCallback() is equivalent to NewRequiredCallback() below.
+  ///
+  /// @param method The method taking the callback. Method should be of type:
+  /// <code>void (T::*)(int32_t result, const A& a, const B& b)</code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] b Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A, typename B>
+  CompletionCallback NewCallback(Method method, const A& a, const B& b) {
+    PP_DCHECK(object_);
+    return NewCallbackHelper(Dispatcher2<Method, A, B>(method, a, b));
+  }
+
+  /// NewRequiredCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code> that will always run. The
+  /// <code>CompletionCallback</code> must be run in order for the memory
+  /// allocated by the methods to be freed.
+  ///
+  /// @param method The method taking the callback. Method should be of type:
+  /// <code>void (T::*)(int32_t result, const A& a, const B& b)</code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] b Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A, typename B>
+  CompletionCallback NewRequiredCallback(Method method, const A& a,
+                                         const B& b) {
+    CompletionCallback cc = NewCallback(method, a, b);
+    cc.set_flags(cc.flags() & ~PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+    return cc;
+  }
+
+  /// NewOptionalCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code> that might not run if the method
+  /// taking it can complete synchronously. Thus, if after passing the
+  /// CompletionCallback to a Pepper method, the method does not return
+  /// PP_OK_COMPLETIONPENDING, then you should manually call the
+  /// CompletionCallback's Run method, or memory will be leaked.
+  ///
+  /// @param[in] method The method taking the callback. Method should be of
+  /// type:
+  /// <code>void (T::*)(int32_t result, const A& a, const B& b)</code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] b Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A, typename B>
+  CompletionCallback NewOptionalCallback(Method method, const A& a,
+                                         const B& b) {
+    CompletionCallback cc = NewCallback(method, a, b);
+    cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+    return cc;
+  }
+
+  /// NewCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code>.
+  /// The <code>CompletionCallback</code> must be run in order for the memory
+  /// allocated by the methods to be freed.
+  /// NewCallback() is equivalent to NewRequiredCallback() below.
+  ///
+  /// @param method The method taking the callback. Method should be of type:
+  /// <code>
+  /// void (T::*)(int32_t result, const A& a, const B& b, const C& c)
+  /// </code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] b Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] c Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A, typename B, typename C>
+  CompletionCallback NewCallback(Method method, const A& a, const B& b,
+                                 const C& c) {
+    PP_DCHECK(object_);
+    return NewCallbackHelper(Dispatcher3<Method, A, B, C>(method, a, b, c));
+  }
+
+  /// NewRequiredCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code> that will always run. The
+  /// <code>CompletionCallback</code> must be run in order for the memory
+  /// allocated by the methods to be freed.
+  ///
+  /// @param method The method taking the callback. Method should be of type:
+  /// <code>
+  /// void (T::*)(int32_t result, const A& a, const B& b, const C& c)
+  /// </code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] b Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] c Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A, typename B, typename C>
+  CompletionCallback NewRequiredCallback(Method method, const A& a,
+                                         const B& b, const C& c) {
+    CompletionCallback cc = NewCallback(method, a, b, c);
+    cc.set_flags(cc.flags() & ~PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+    return cc;
+  }
+
+  /// NewOptionalCallback() allocates a new, single-use
+  /// <code>CompletionCallback</code> that might not run if the method
+  /// taking it can complete synchronously. Thus, if after passing the
+  /// CompletionCallback to a Pepper method, the method does not return
+  /// PP_OK_COMPLETIONPENDING, then you should manually call the
+  /// CompletionCallback's Run method, or memory will be leaked.
+  ///
+  /// @param[in] method The method taking the callback. Method should be of
+  /// type:
+  /// <code>
+  /// void (T::*)(int32_t result, const A& a, const B& b, const C& c)
+  /// </code>
+  ///
+  /// @param[in] a Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] b Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @param[in] c Passed to <code>method</code> when the completion callback
+  /// runs.
+  ///
+  /// @return A <code>CompletionCallback</code>.
+  template <typename Method, typename A, typename B, typename C>
+  CompletionCallback NewOptionalCallback(Method method, const A& a,
+                                         const B& b, const C& c) {
+    CompletionCallback cc = NewCallback(method, a, b, c);
+    cc.set_flags(cc.flags() | PP_COMPLETIONCALLBACK_FLAG_OPTIONAL);
+    return cc;
+  }
+
+ private:
+  class BackPointer {
+   public:
+    typedef CompletionCallbackFactory<T, RefCount> FactoryType;
+
+    BackPointer(FactoryType* factory)
+        : factory_(factory) {
+    }
+
+    void AddRef() {
+      ref_.AddRef();
+    }
+
+    void Release() {
+      if (ref_.Release() == 0)
+        delete this;
+    }
+
+    void DropFactory() {
+      factory_ = NULL;
+    }
+
+    T* GetObject() {
+      return factory_ ? factory_->GetObject() : NULL;
+    }
+
+   private:
+    RefCount ref_;
+    FactoryType* factory_;
+  };
+
+  template <typename Dispatcher>
+  class CallbackData {
+   public:
+    CallbackData(BackPointer* back_pointer, const Dispatcher& dispatcher)
+        : back_pointer_(back_pointer),
+          dispatcher_(dispatcher) {
+      back_pointer_->AddRef();
+    }
+
+    ~CallbackData() {
+      back_pointer_->Release();
+    }
+
+    static void Thunk(void* user_data, int32_t result) {
+      Self* self = static_cast<Self*>(user_data);
+      T* object = self->back_pointer_->GetObject();
+      if (object)
+        self->dispatcher_(object, result);
+      delete self;
+    }
+
+   private:
+    typedef CallbackData<Dispatcher> Self;
+    BackPointer* back_pointer_;
+    Dispatcher dispatcher_;
+  };
+
+  template <typename Method>
+  class Dispatcher0 {
+   public:
+    Dispatcher0(Method method) : method_(method) {
+    }
+    void operator()(T* object, int32_t result) {
+      (object->*method_)(result);
+    }
+   private:
+    Method method_;
+  };
+
+  template <typename Method, typename A>
+  class Dispatcher1 {
+   public:
+    Dispatcher1(Method method, const A& a)
+        : method_(method),
+          a_(a) {
+    }
+    void operator()(T* object, int32_t result) {
+      (object->*method_)(result, a_);
+    }
+   private:
+    Method method_;
+    A a_;
+  };
+
+  template <typename Method, typename A, typename B>
+  class Dispatcher2 {
+   public:
+    Dispatcher2(Method method, const A& a, const B& b)
+        : method_(method),
+          a_(a),
+          b_(b) {
+    }
+    void operator()(T* object, int32_t result) {
+      (object->*method_)(result, a_, b_);
+    }
+   private:
+    Method method_;
+    A a_;
+    B b_;
+  };
+
+  template <typename Method, typename A, typename B, typename C>
+  class Dispatcher3 {
+   public:
+    Dispatcher3(Method method, const A& a, const B& b, const C& c)
+        : method_(method),
+          a_(a),
+          b_(b),
+          c_(c) {
+    }
+    void operator()(T* object, int32_t result) {
+      (object->*method_)(result, a_, b_, c_);
+    }
+   private:
+    Method method_;
+    A a_;
+    B b_;
+    C c_;
+  };
+
+  void InitBackPointer() {
+    back_pointer_ = new BackPointer(this);
+    back_pointer_->AddRef();
+  }
+
+  void ResetBackPointer() {
+    back_pointer_->DropFactory();
+    back_pointer_->Release();
+  }
+
+  template <typename Dispatcher>
+  CompletionCallback NewCallbackHelper(const Dispatcher& dispatcher) {
+    PP_DCHECK(object_);  // Expects a non-null object!
+    return CompletionCallback(
+        &CallbackData<Dispatcher>::Thunk,
+        new CallbackData<Dispatcher>(back_pointer_, dispatcher));
+  }
+
+  // Disallowed:
+  CompletionCallbackFactory(const CompletionCallbackFactory&);
+  CompletionCallbackFactory& operator=(const CompletionCallbackFactory&);
+
+  T* object_;
+  BackPointer* back_pointer_;
+};
+
+}  // namespace pp
+
+#endif  // PPAPI_UTILITY_COMPLETION_CALLBACK_FACTORY_H_