Clean up CF To NS Casts and make them slightly safer

chrome/browser/cocoa/install_from_dmg.mm

 // Copyright (c) 2010 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/cocoa/install_from_dmg.h"
 
 #include <ApplicationServices/ApplicationServices.h>
 #import <AppKit/AppKit.h>
 #include <CoreFoundation/CoreFoundation.h>
 #include <CoreServices/CoreServices.h>
@@ skipping 221 matching lines @@
 AuthorizationRef MaybeShowAuthorizationDialog(NSString* application_directory) {
   NSFileManager* file_manager = [NSFileManager defaultManager];
   if ([file_manager isWritableFileAtPath:application_directory]) {
     return NULL;
   }
 
   NSString* prompt = l10n_util::GetNSStringFWithFixup(
       IDS_INSTALL_FROM_DMG_AUTHENTICATION_PROMPT,
       l10n_util::GetStringUTF16(IDS_PRODUCT_NAME));
   return authorization_util::AuthorizationCreateToRunAsRoot(
-      reinterpret_cast<CFStringRef>(prompt));
+      base::mac::NSToCFCast(prompt));
 }
 
 // Invokes the installer program at installer_path to copy source_path to
 // target_path and perform any additional on-disk bookkeeping needed to be
 // able to launch target_path properly.  If authorization_arg is non-NULL,
 // function will assume ownership of it, will invoke the installer with that
 // authorization reference, and will attempt Keystone ticket promotion.
 bool InstallFromDiskImage(AuthorizationRef authorization_arg,
                           NSString* installer_path,
                           NSString* source_path,
@@ skipping 79 matching lines @@
     const int psn_flag_length = arraysize(psn_flag) - 1;
     if (argument.compare(0, psn_flag_length, psn_flag) != 0) {
       // Strip any -psn_ arguments, as they apply to a specific process.
       [arguments addObject:[NSString stringWithUTF8String:argument.c_str()]];
     }
   }
 
   struct LSApplicationParameters parameters = {0};
   parameters.flags = kLSLaunchDefaults;
   parameters.application = &app_fsref;
-  parameters.argv = reinterpret_cast<CFArrayRef>(arguments);
+  parameters.argv = base::mac::NSToCFCast(arguments);
 
   err = LSOpenApplication(&parameters, NULL);
   if (err != noErr) {
     LOG(ERROR) << "LSOpenApplication: " << err;
     return false;
   }
 
   return true;
 }
 
@@ skipping 76 matching lines @@
                             installer_path,
                             source_path,
                             target_path) ||
       !LaunchInstalledApp(target_path)) {
     ShowErrorDialog();
     return false;
   }
 
   return true;
 }