Make installed_loader UMA less wasteful.

extensions/common/manifest.h

 // 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.
 
 #ifndef EXTENSIONS_COMMON_MANIFEST_H_
 #define EXTENSIONS_COMMON_MANIFEST_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 44 matching lines @@
   enum Type {
     TYPE_UNKNOWN = 0,
     TYPE_EXTENSION,
     TYPE_THEME,
     TYPE_USER_SCRIPT,
     TYPE_HOSTED_APP,
     // This is marked legacy because platform apps are preferred. For
     // backwards compatibility, we can't remove support for packaged apps
     TYPE_LEGACY_PACKAGED_APP,
     TYPE_PLATFORM_APP,
-    TYPE_SHARED_MODULE
+    TYPE_SHARED_MODULE,
+    NUM_LOAD_TYPES

[Devlin, 2014/05/21 19:54:09]

nit: We should probably include the standard comment about "any new types should
go above this one"

[jar (doing other things), 2014/05/21 22:12:45]

+1

[not at google - send to devlin, 2014/05/21 23:17:22]

Done.

   };
 
   // Given two install sources, return the one which should take priority
   // over the other. If an extension is installed from two sources A and B,
   // its install source should be set to GetHigherPriorityLocation(A, B).
   static Location GetHigherPriorityLocation(Location loc1, Location loc2);
 
   // Whether the |location| is external or not.
   static inline bool IsExternalLocation(Location location) {
     return location == EXTERNAL_PREF ||
@@ skipping 113 matching lines @@
   scoped_ptr<base::DictionaryValue> value_;
 
   Type type_;
 
   DISALLOW_COPY_AND_ASSIGN(Manifest);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_MANIFEST_H_