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

chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.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.
 
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.h"
 
 #import "base/mac/mac_util.h"
 #include "base/mac/scoped_cftyperef.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_controller.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_controller_target.h"
@@ skipping 520 matching lines @@
       NULL, reinterpret_cast<const void **>(&windowID), 1, NULL));
   base::mac::ScopedCFTypeRef<CFArrayRef> descriptions(
       CGWindowListCreateDescriptionFromArray(windowIDs));
   DCHECK(CFArrayGetCount(descriptions.get()) <= 1);
   if (CFArrayGetCount(descriptions.get()) > 0) {
     CFDictionaryRef dict = static_cast<CFDictionaryRef>(
         CFArrayGetValueAtIndex(descriptions.get(), 0));
     DCHECK(CFGetTypeID(dict) == CFDictionaryGetTypeID());
 
     // Sanity check the ID.
-    CFNumberRef otherIDRef = (CFNumberRef)base::mac::GetValueFromDictionary(
-        dict, kCGWindowNumber, CFNumberGetTypeID());
+    CFNumberRef otherIDRef =
+        base::mac::GetValueFromDictionary<CFNumberRef>(dict, kCGWindowNumber);
     CGWindowID otherID;
     if (otherIDRef &&
         CFNumberGetValue(otherIDRef, kCGWindowIDCFNumberType, &otherID) &&
         otherID == windowID) {
       // And then get the workspace.
-      CFNumberRef workspaceRef = (CFNumberRef)base::mac::GetValueFromDictionary(
-          dict, kCGWindowWorkspace, CFNumberGetTypeID());
+      CFNumberRef workspaceRef =
+          base::mac::GetValueFromDictionary<CFNumberRef>(dict,
+                                                         kCGWindowWorkspace);
       if (!workspaceRef ||
           !CFNumberGetValue(workspaceRef, kCFNumberIntType, &workspace)) {
         workspace = -1;
       }
     } else {
       NOTREACHED();
     }
   }
   if (useCache) {
     workspaceIDCache_[windowID] = workspace;
   }
   return workspace;
 }
 
 @end