Add Linux support for the Bluetooth API.

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 43b9ef9607a326b988c7d421c6f0847fb1cf4c81..67a2dceefe11efb744b9e420987678994cb4f1c1 100644
--- a/extensions/common/api/_manifest_features.json
+++ b/extensions/common/api/_manifest_features.json
@@ -74,7 +74,7 @@
     "extension_types": ["platform_app"],
     "platforms": ["chromeos", "win", "mac"]
   }, {
-    "channel": "stable",
+    "channel": "trunk",

[Ken Rockot(use gerrit already), 2015/09/23 20:12:53]

Is this really what you want to do?

[jdeokule, 2015/09/23 20:22:52]

Yes, we would like these whitelisted before it hits stable so we can test early.

[rkc, 2015/09/23 20:26:42]

Yep. Their team will need to use this with build just pulled from ToT.

[Ken Rockot(use gerrit already), 2015/09/23 20:27:21]

The old configuration whitelists the API on all channels stable and newer. The
configuration whitelists the API only on trunk, meaning dev, beta, and stable
channels will not have the whitelist active.

[rkc, 2015/09/23 20:32:34]

Whoops, that is exactly the opposite of what I meant. Fixed.
Done.

     "extension_types": ["platform_app"],
     "platforms": ["linux"],
     "whitelist": [