Bug 795259 - Disable screenshot layer in Firefox for Android. r=blassey

mobile/android/app/mobile.js

@@ -343,7 +343,7 @@ pref("gfx.displayport.strategy_vb.danger_y_incr", -1); // additional danger zone
 // prediction bias strategy options
 pref("gfx.displayport.strategy_pb.threshold", -1); // velocity threshold in inches/frame
 
-pref("gfx.java.screenshot.enabled", true);
+pref("gfx.java.screenshot.enabled", false);
 
 // don't allow JS to move and resize existing windows
 pref("dom.disable_window_move_resize", true);