Use the new base::mac::GetValueFromDictionary<>() method.

base/mac/foundation_util.mm

 // Copyright (c) 2011 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 "base/mac/foundation_util.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 #include "base/file_path.h"
@@ skipping 199 matching lines @@
 TYPE_NAME_FOR_CF_TYPE_DEFN(CFData);
 TYPE_NAME_FOR_CF_TYPE_DEFN(CFDate);
 TYPE_NAME_FOR_CF_TYPE_DEFN(CFDictionary);
 TYPE_NAME_FOR_CF_TYPE_DEFN(CFNull);
 TYPE_NAME_FOR_CF_TYPE_DEFN(CFNumber);
 TYPE_NAME_FOR_CF_TYPE_DEFN(CFSet);
 TYPE_NAME_FOR_CF_TYPE_DEFN(CFString);
 
 #undef TYPE_NAME_FOR_CF_TYPE_DEFN
 
-std::string GetValueFromDictionaryErrorMessage(
-    CFStringRef key, const std::string& expected_type, CFTypeRef value) {
-  ScopedCFTypeRef<CFStringRef> actual_type_ref(
-      CFCopyTypeIDDescription(CFGetTypeID(value)));
-  return "Expected value for key " +
-      base::SysCFStringRefToUTF8(key) +
-      " to be " +
-      expected_type +
-      " but it was " +
-      base::SysCFStringRefToUTF8(actual_type_ref) +
-      " instead";
-}
-
-CFTypeRef GetValueFromDictionary(CFDictionaryRef dict,
-                                 CFStringRef key,
-                                 CFTypeID expected_type) {
-  CFTypeRef value = CFDictionaryGetValue(dict, key);
-  if (!value)
-    return value;
-
-  if (CFGetTypeID(value) != expected_type) {
-    ScopedCFTypeRef<CFStringRef> expected_type_name(
-        CFCopyTypeIDDescription(expected_type));
-    std::string expected_type_utf8 =
-        base::SysCFStringRefToUTF8(expected_type_name);
-    DLOG(WARNING) << GetValueFromDictionaryErrorMessage(key,
-                                                        expected_type_utf8,
-                                                        value);
-    return NULL;
-  }
-
-  return value;
-}
-
 void NSObjectRetain(void* obj) {
   id<NSObject> nsobj = static_cast<id<NSObject> >(obj);
   [nsobj retain];
 }
 
 void NSObjectRelease(void* obj) {
   id<NSObject> nsobj = static_cast<id<NSObject> >(obj);
   [nsobj release];
 }
 
@@ skipping 108 matching lines @@
 CF_CAST_DEFN(CFData);
 CF_CAST_DEFN(CFDate);
 CF_CAST_DEFN(CFDictionary);
 CF_CAST_DEFN(CFNull);
 CF_CAST_DEFN(CFNumber);
 CF_CAST_DEFN(CFSet);
 CF_CAST_DEFN(CFString);
 
 #undef CF_CAST_DEFN
 
+std::string GetValueFromDictionaryErrorMessage(
+    CFStringRef key, const std::string& expected_type, CFTypeRef value) {
+  ScopedCFTypeRef<CFStringRef> actual_type_ref(
+      CFCopyTypeIDDescription(CFGetTypeID(value)));
+  return "Expected value for key " +
+      base::SysCFStringRefToUTF8(key) +
+      " to be " +
+      expected_type +
+      " but it was " +
+      base::SysCFStringRefToUTF8(actual_type_ref) +
+      " instead";
+}
+
 }  // namespace mac
 }  // namespace base
 
 std::ostream& operator<<(std::ostream& o, const CFStringRef string) {
   return o << base::SysCFStringRefToUTF8(string);
 }
 
 std::ostream& operator<<(std::ostream& o, const CFErrorRef err) {
   base::mac::ScopedCFTypeRef<CFStringRef> desc(CFErrorCopyDescription(err));
   base::mac::ScopedCFTypeRef<CFDictionaryRef> user_info(
       CFErrorCopyUserInfo(err));
   CFStringRef errorDesc = NULL;
   if (user_info.get()) {
     errorDesc = reinterpret_cast<CFStringRef>(
         CFDictionaryGetValue(user_info.get(), kCFErrorDescriptionKey));
   }
   o << "Code: " << CFErrorGetCode(err)
     << " Domain: " << CFErrorGetDomain(err)
     << " Desc: " << desc.get();
   if(errorDesc) {
     o << "(" << errorDesc << ")";
   }
   return o;
 }