Enable content_capabilities on dev channel

extensions/common/api/_manifest_features.json

Index: extensions/common/api/_manifest_features.json
diff --git a/extensions/common/api/_manifest_features.json b/extensions/common/api/_manifest_features.json
index 0d04b6db2af04e47752065fed320772c437520a0..4c2a471f6d080df2827d5eedb1835c57a23a52d8 100644
--- a/extensions/common/api/_manifest_features.json
+++ b/extensions/common/api/_manifest_features.json
@@ -86,13 +86,16 @@
       "81986D4F846CEDDDB962643FA501D1780DD441BB"   // http://crbug.com/407693
     ]
   }],
-  "content_capabilities": {
+  "content_capabilities": [{
     "channel": "stable",
     "extension_types": ["extension"],
     "whitelist": [
       "950D13BB9B4794F4CA2A68D3597E5DFAA47C88AE"  // Drive
     ]
-  },
+  }, {
+    "channel": "dev",

[not at google - send to devlin, 2015/03/04 17:37:45]

You could also enable on canary only, if this is just for the purpose of
testing?

+    "extension_types": ["extension"]
+  }],
   "content_security_policy": {
     "channel": "stable",
     // Platform apps have a restricted content security policy that cannot be