Enable the object-shorthand ESLint rule in src/display

Please see http://eslint.org/docs/rules/object-shorthand.

For the most part, these changes are of the search-and-replace kind, and the previously enabled `no-undef` rule should complement the tests in helping ensure that no stupid errors crept into to the patch.

src/display/webgl.js

@@ -430,8 +430,8 @@ var WebGLUtils = (function WebGLUtilsClosure() {
       } catch (e) { }
       return shadow(this, 'isEnabled', enabled);
     },
-    composeSMask: composeSMask,
-    drawFigures: drawFigures,
+    composeSMask,
+    drawFigures,
     clear: cleanup
   };
 })();