mac: Crash on uncaught Objective-C exceptions routed to NSApplication

content/app/mac/mac_init.mm

 // Copyright 2015 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 "content/app/mac/mac_init.h"
 
-#include <Cocoa/Cocoa.h>
+#import <Cocoa/Cocoa.h>
 
 #include "base/mac/mac_util.h"
 
 namespace content {
 
 void InitializeMac() {
   [[NSUserDefaults standardUserDefaults] registerDefaults:@{
+      // Exceptions routed to -[NSApplication reportException:] should crash
+      // immediately, as opposed being swallowed or presenting UI that gives the
+      // user a choice in the matter.
+      @"NSApplicationCrashOnExceptions": @YES,
+
+      // Prevent Cocoa from turning command-line arguments into -[NSApplication
+      // application:openFile:], because they are handled directly. @"NO" looks
+      // like a mistake, but the value really is supposed to be a string.
       @"NSTreatUnknownArgumentsAsOpen": @"NO",
+
       // CoreAnimation has poor performance and CoreAnimation and
       // non-CoreAnimation exhibit window flickering when layers are not hosted
       // in the window server, which is the default when not not using the
       // 10.9 SDK.
       // TODO: Remove this when we build with the 10.9 SDK.
       @"NSWindowHostsLayersInWindowServer": @(base::mac::IsOSMavericksOrLater())
   }];
 }
 
 }  // namespace content