Whitelist MR extensions for settingsPrivate 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 671d5716896496fac5590de40cf709a7e3d7e1b8..3e6242dac99dd99f7543ab91d53440433aa7fa0c 100644
--- a/chrome/common/extensions/api/_permission_features.json
+++ b/chrome/common/extensions/api/_permission_features.json
@@ -924,11 +924,21 @@
     "channel": "stable",
     "extension_types": ["extension", "legacy_packaged_app"]
   },
-  "settingsPrivate": {
-    "channel": "trunk",
-    "extension_types": ["extension", "platform_app"],
-    "location": "component"
-  },
+  "settingsPrivate": [

[Devlin, 2016/01/28 22:55:59]

We're quite inconsistent in style, but I'd prefer to see us using the { on the
previous line, a la line 874.  It feels more concise.

[amp, 2016/01/28 23:09:10]

Done.

+    {
+      "channel": "trunk",
+      "extension_types": ["extension", "platform_app"],
+      "location": "component"
+    },
+    {
+      "channel": "stable",
+      "extension_types": ["extension"],
+      "whitelist": [
+        "63ED55E43214C211F82122ED56407FF1A807F2A3",  // Media Router Dev
+        "226CF815E39A363090A1E547D53063472B8279FA"   // Media Router Release
+      ]
+    }
+  ],
   "signedInDevices": {
     "channel": "dev",
     "extension_types": ["extension", "legacy_packaged_app", "platform_app"]