Bug 1343984 - Turn on warnings-as-errors for webrender_bindings. r=jrmuizel

MozReview-Commit-ID: C8r1IwbQP7g

gfx/webrender_bindings/src/lib.rs

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#![deny(warnings)]
+
 extern crate webrender;
 extern crate webrender_traits;
 extern crate euclid;