Add DeviceADPolicyManager to provide AD policy.

components/policy/core/common/policy_map.cc

 // Copyright 2013 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 "components/policy/core/common/policy_map.h"
 
 #include <algorithm>
 
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
@@ skipping 71 matching lines @@
   entry.source = source;
   entry.value = std::move(value);
   entry.external_data_fetcher = std::move(external_data_fetcher);
   Set(policy, std::move(entry));
 }
 
 void PolicyMap::Set(const std::string& policy, Entry entry) {
   map_[policy] = std::move(entry);
 }
 
+void PolicyMap::SetSourceForAll(PolicySource source) {
+  for (auto& it : map_) {
+    it.second.source = source;
+  }
+}
+
 void PolicyMap::Erase(const std::string& policy) {
   map_.erase(policy);
 }
 
 void PolicyMap::EraseMatching(
     const base::Callback<bool(const const_iterator)>& filter) {
   FilterErase(filter, true);
 }
 
 void PolicyMap::EraseNonmatching(
@@ skipping 102 matching lines @@
   while (iter != map_.end()) {
     if (filter.Run(iter) == deletion_value) {
       map_.erase(iter++);
     } else {
       ++iter;
     }
   }
 }
 
 }  // namespace policy