Made return types of various Value::DeepCopy() implementations more specific

chrome/browser/policy/device_management_policy_cache.cc

 // 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/policy/device_management_policy_cache.h"
 
 #include <limits>
 #include <string>
 
 #include "base/file_util.h"
@@ skipping 117 matching lines @@
   policy_copy->CopyFrom(policy);
   BrowserThread::PostTask(
       BrowserThread::FILE,
       FROM_HERE,
       new PersistPolicyTask(backing_file_path_, policy_copy, now, false));
   return new_policy_differs;
 }
 
 DictionaryValue* DeviceManagementPolicyCache::GetPolicy() {
   AutoLock lock(lock_);
-  return static_cast<DictionaryValue*>(policy_->DeepCopy());
+  return policy_->DeepCopy();
 }
 
 void DeviceManagementPolicyCache::SetDeviceUnmanaged(bool is_device_unmanaged) {
   if (is_device_unmanaged_ == is_device_unmanaged)
     return;
 
   is_device_unmanaged_ = is_device_unmanaged;
   base::Time now(base::Time::NowFromSystemTime());
   DictionaryValue* empty = new DictionaryValue();
   {
@@ skipping 120 matching lines @@
             DeviceManagementPolicyCache::DecodeValue(named_value->value());
         if (decoded_value)
           result->Set(named_value->name(), decoded_value);
       }
     }
   }
   return result;
 }
 
 }  // namespace policy