Make installed_loader UMA less wasteful.

extensions/common/manifest.h

Index: extensions/common/manifest.h
diff --git a/extensions/common/manifest.h b/extensions/common/manifest.h
index a50e724c5792814e0c4c99962da0e031d1d04638..b6039f62064547c02af0153a779fe7cf0a1f958c 100644
--- a/extensions/common/manifest.h
+++ b/extensions/common/manifest.h
@@ -62,7 +62,8 @@ class Manifest {
     // 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