Clean up CF To NS Casts and make them slightly safer

chrome/browser/ui/cocoa/file_metadata.mm

 // Copyright (c) 2009 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/file_metadata.h"
 
 #include <ApplicationServices/ApplicationServices.h>
 #include <Foundation/Foundation.h>
 
 #include "base/file_path.h"
@@ skipping 52 matching lines @@
   }
   if (!md_item_set_attribute_func)
     return;
 
   NSString* file_path =
       [NSString stringWithUTF8String:file.value().c_str()];
   if (!file_path)
     return;
 
   base::mac::ScopedCFTypeRef<MDItemRef> md_item(
-      MDItemCreate(NULL, reinterpret_cast<CFStringRef>(file_path)));
+      MDItemCreate(NULL, base::mac::NSToCFCast(file_path)));
   if (!md_item)
     return;
 
   // We won't put any more than 2 items into the attribute.
   NSMutableArray* list = [NSMutableArray arrayWithCapacity:2];
 
   // Follow Safari's lead: the first item in the list is the source URL of
   // the downloaded file. If the referrer is known, store that, too.
   NSString* origin_url = [NSString stringWithUTF8String:source.spec().c_str()];
   if (origin_url)
     [list addObject:origin_url];
   NSString* referrer_url =
       [NSString stringWithUTF8String:referrer.spec().c_str()];
   if (referrer_url)
     [list addObject:referrer_url];
 
   md_item_set_attribute_func(md_item, kMDItemWhereFroms,
-                             reinterpret_cast<CFArrayRef>(list));
+                             base::mac::NSToCFCast(list));
 }
 
 // The OS will automatically quarantine files due to the
 // LSFileQuarantineEnabled entry in our Info.plist, but it knows relatively
 // little about the files. We add more information about the download to
 // improve the UI shown by the OS when the users tries to open the file.
 void AddQuarantineMetadataToFile(const FilePath& file, const GURL& source,
                                  const GURL& referrer) {
   FSRef file_ref;
   if (!base::mac::FSRefFromPath(file.value(), &file_ref))
@@ skipping 56 matching lines @@
   OSStatus os_error = LSSetItemAttribute(&file_ref, kLSRolesAll,
                                          kLSItemQuarantineProperties,
                                          quarantine_properties);
   if (os_error != noErr) {
     LOG(WARNING) << "Unable to set quarantine attributes on file "
                  << file.value();
   }
 }
 
 }  // namespace file_metadata