Add EXTERNAL_POLICY to list of possible extension locations

extensions/common/manifest.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 "extensions/common/manifest.h"
 
 #include "base/basictypes.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/strings/string_split.h"
@@ skipping 16 matching lines @@
 // An extension installed from two locations will have the location
 // with the higher rank, as returned by this function. The actual
 // integer values may change, and should never be persisted.
 int GetLocationRank(Manifest::Location location) {
   const int kInvalidRank = -1;
   int rank = kInvalidRank;  // Will CHECK that rank is not kInvalidRank.
 
   switch (location) {
     // Component extensions can not be overriden by any other type.
     case Manifest::COMPONENT:
-      rank = 7;
+      rank = 8;
       break;
 
     // Policy controlled extensions may not be overridden by any type
     // that is not part of chrome.
+    case Manifest::EXTERNAL_POLICY:
+      rank = 7;
+      break;
+
     case Manifest::EXTERNAL_POLICY_DOWNLOAD:
       rank = 6;
       break;
 
     // A developer-loaded extension should override any installed type
     // that a user can disable. Anything specified on the command-line should
     // override one loaded via the extensions UI.
     case Manifest::COMMAND_LINE:
       rank = 5;
       break;
@@ skipping 196 matching lines @@
   Feature* feature = FeatureProvider::GetByName("manifest")->GetFeature(key);
   if (!feature)
     return true;
 
   return feature->IsAvailableToManifest(
       extension_id_, type_, Feature::ConvertLocation(location_),
       GetManifestVersion()).is_available();
 }
 
 }  // namespace extensions