fileSystemProvider: First cut at implementing fileSystemProvider API

chrome/common/extensions/api/_permission_features.json

Index: chrome/common/extensions/api/_permission_features.json
diff --git a/chrome/common/extensions/api/_permission_features.json b/chrome/common/extensions/api/_permission_features.json
index ca2ee0c1362f4cb3f0f633edd6fab8b5f8458cbd..0a55c18eb6a5f0e81ce2d1c1e4ce70bf108ec0f3 100644
--- a/chrome/common/extensions/api/_permission_features.json
+++ b/chrome/common/extensions/api/_permission_features.json
@@ -334,6 +334,10 @@
     "extension_types": ["extension"],
     "whitelist": [ "2FC374607C2DF285634B67C64A2E356C607091C3" ]
   }],
+  "fileSystemProvider": {
+    "channel": "trunk",
+    "extension_types": ["platform_app"]

[kinuko, 2013/10/30 10:45:05]

So are we going to implement this as a platform_app API or it's tentative and
we'll revisit this later?

[satorux1, 2013/10/31 01:51:26]

It's tentative. At this moment, I'm thinking about platform apps without icons
in the app launcher (you can do this with "display_in_launcher": false in
manifest.json).

+  },
   "fontSettings": {
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app"]