Bug 1147753. Disable vsync refresh driver on L devices. r=kats

b2g/app/b2g.js

@@ -1131,10 +1131,16 @@ pref("dom.requestSync.enabled", true);
 pref("gfx.vsync.hw-vsync.enabled", true);
 pref("gfx.vsync.compositor", true);
 pref("gfx.touch.resample", true);
-pref("gfx.vsync.refreshdriver", true);
 #else
 pref("gfx.vsync.hw-vsync.enabled", false);
 pref("gfx.vsync.compositor", false);
 pref("gfx.touch.resample", false);
+#endif
+
+// Bug 1147753 - Weird issues with vsync refresh driver on L devices
+// so disable them on L, but enable on KK and ICS
+#if ANDROID_VERSION == 19 || ANDROID_VERSION == 15
+pref("gfx.vsync.refreshdriver", true);
+#else
 pref("gfx.vsync.refreshdriver", false);
 #endif