Set empty icon to alert dialogs on mac

chrome/browser/ui/cocoa/javascript_app_modal_dialog_cocoa.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.
 
 #include "chrome/browser/ui/cocoa/javascript_app_modal_dialog_cocoa.h"
 
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
 #include "base/i18n/rtl.h"
@@ skipping 63 matching lines @@
 
 - (instancetype)initWithNativeDialog:(JavaScriptAppModalDialogCocoa*)dialog {
   DCHECK(dialog);
   self = [super init];
   if (self)
     nativeDialog_ = dialog;
   return self;
 }
 
 - (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_;
 }
 
 - (void)addTextFieldWithPrompt:(NSString*)prompt {
   DCHECK(!textField_);
   textField_.reset(
       [[NSTextField alloc] initWithFrame:NSMakeRect(0, 0, 300, 22)]);
   [[textField_ cell] setLineBreakMode:NSLineBreakByTruncatingTail];
   [[self alert] setAccessoryView:textField_];
   [[alert_ window] setInitialFirstResponder:textField_];
@@ skipping 363 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(ChromeJavaScriptNativeDialogCocoaFactory);
 };
 
 }  // namespace
 
 void InstallChromeJavaScriptNativeDialogFactory() {
   app_modal::JavaScriptDialogManager::GetInstance()->
       SetNativeDialogFactory(
           make_scoped_ptr(new ChromeJavaScriptNativeDialogCocoaFactory));
 }