[Mac] In BrowserWindowCocoa::Close() do not use -[NSWindow performClose:].

chrome/browser/ui/cocoa/browser_window_cocoa.mm

Index: chrome/browser/ui/cocoa/browser_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/browser_window_cocoa.mm b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
index 31116d4f1b1a3370dfabfe9c0bca767f58a50207..c84f07f8f85a1c7ae94c35a117cacc923d6f9650 100644
--- a/chrome/browser/ui/cocoa/browser_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/browser_window_cocoa.mm
@@ -170,7 +170,17 @@ void BrowserWindowCocoa::Close() {
   if ([controller_ overlayWindow]) {
     [controller_ deferPerformClose];
   } else {
-    [window() performClose:controller_];
+    // Using |-performClose:| can prevent the window from actually closing if
+    // a JavaScript beforeunload handler opens an alert during shutdown, as
+    // documented at <http://crbug.com/118424>. Re-implement
+    // -[NSWindow performClose:] as closely as possible to how Apple documents
+    // it. Note that this implementation assumes that NSWindow does not
+    // implement |-windowShouldClose:|.

[Mark Mentovai, 2012/10/10 18:43:09]

It wouldn’t be difficult to send the message to the window if the delegate
doesn’t implement -windowShouldClose:. The assumption that our windows have
delegates to deal with this may be valid today, but I wouldn’t count on that
remaining valid indefinitely.

[Robert Sesek, 2012/10/11 14:13:37]

Done. There's a new test for you to review, too.

+    id<NSWindowDelegate> delegate = [window() delegate];
+    if (![delegate respondsToSelector:@selector(windowShouldClose:)] ||

[Mark Mentovai, 2012/10/10 18:43:09]

What is this weird bracket syntax?

[Robert Sesek, 2012/10/11 14:13:37]

http://bukk.it/noidea-golf.gif

+        [delegate windowShouldClose:window()]) {
+      [window() close];
+    }
   }
 }