Set empty icon to alert dialogs on mac

chrome/browser/ui/cocoa/javascript_app_modal_dialog_cocoa.mm

Index: chrome/browser/ui/cocoa/javascript_app_modal_dialog_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/javascript_app_modal_dialog_cocoa.mm b/chrome/browser/ui/cocoa/javascript_app_modal_dialog_cocoa.mm
index fa6d65f95eb8f30e4324317d593a1f0a81d7f58b..6ad973e3654b7a1341d01fb8ec480b14a4b9666c 100644
--- a/chrome/browser/ui/cocoa/javascript_app_modal_dialog_cocoa.mm
+++ b/chrome/browser/ui/cocoa/javascript_app_modal_dialog_cocoa.mm
@@ -81,8 +81,10 @@ const int kMessageTextMaxSlots = 2000;
 }
 
 - (NSAlert*)alert {
-  if (!alert_)
+  if (!alert_) {
     alert_.reset([[NSAlert alloc] init]);
+    [alert_ setIcon:[NSImage new]];

[meacer, 2016/02/04 22:17:58]

Not sure about the ownership here, does alert own the icon?

[droger, 2016/02/05 10:33:01]

Drive-by.
I expect this to be a memory leak.

Does [alert_ setIcon:nil]; work?

Otherwise, I'd think that something like this would be more appropriate:

base::scoped_nsobject<NSImage> emptyIcon_([[NSImage alloc] init]);
[alert_ setIcon:emptyIcon_.get()];

[Avi (use Gerrit), 2016/02/05 17:06:09]

It'll make its own reference, so you're leaking here.

Maybe:
NSImage* image = [[[NSImage alloc] initWithSize:NSMakeSize(1,1)] autorelease];
[alert_ setIcon:image];

[Avi (use Gerrit), 2016/02/05 17:11:23]

Gah, yes. I replied but forgot to mail my comments :(

The problem with [alert_ setIcon:nil] is that icon is a null_resettable
property, so setting it to nil is just going to use the default application
icon. If you want a blank icon, you need to specify a blank icon.

[meacer, 2016/02/05 19:37:16]

Done, thanks for the snippet.

+  }
   return alert_;
 }