Bug 1532284 - Fix rustc compiler warnings when building wrench for Android. r=gw
Bug 1532284 - Fix rustc compiler warnings when building wrench for Android. r=gw

Various variables are unused when building for Android.

Differential Revision: https://phabricator.services.mozilla.com/D22376

[wrupdater] From https://hg.mozilla.org/mozilla-central/rev/3dc8bca5dd907f77bebb648baf412c6276022750

servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender