Adding the possibility to build a closure from an ObjectiveC block.

base/mac/bind_objc_block.mm

+// Copyright (c) 2012 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.
+
+#import "base/mac/bind_objc_block.h"
+
+#include "base/bind.h"
+#include "base/memory/scoped_nsobject.h"
+
+namespace {

[Mark Mentovai, 2012/07/25 14:06:30]

Blank line after this one, and another blank line before line 16, the “}  //
namespace” line. Namespace formatting is covered at
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Namesp...
. You did the right thing for the base namespace below.

[noyau (Ping after 24h), 2012/07/25 14:27:58]

Done. I would point out however that the extra lines are not explicitly required
anywhere that I could find and that the last example on the style guide do not
include them either.

+// Run the block contained in the parameter.
+void RunBlock(scoped_nsobject<id> block) {

[Mark Mentovai, 2012/07/25 14:06:30]

If RunBlock is never called, block is never freed. Can that happen? Does that
happen? Is this OK?

ajwong may have suggestions.

[noyau (Ping after 24h), 2012/07/25 14:27:58]

I am not sure I follow. The block is retained by the Callback returned by Bind,
and is released when the Callback is freed, not when RunBlock is invoked.
RunBlock can be invoked multiple times if needed. 

+  void(^extracted_block)() = block.get();
+  extracted_block();
+}
+}  // namespace

[Mark Mentovai, 2012/07/25 14:06:30]

Blank line before this one.

[noyau (Ping after 24h), 2012/07/25 14:27:58]

Done.

+
+namespace base {
+
+base::Closure BindBlock(void(^block)()) {
+  return base::Bind(&RunBlock, scoped_nsobject<id>([block copy]));
+}
+
+}  // namespace base