Drain any pending touch events immediately if possible

Bug: 6317798

Change-Id: Id343801cf80817f587414224cc67c13d34efed04

core/java/android/webkit/WebViewClassic.java

@@ -5754,6 +5754,7 @@ public final class WebViewClassic implements WebViewProvider, WebViewProvider.Sc
 
         if (mInputDispatcher.postPointerEvent(ev, getScrollX(),
                 getScrollY() - getTitleHeight(), mZoomManager.getInvScale())) {
+            mInputDispatcher.dispatchUiEvents();
             return true;
         } else {
             Log.w(LOGTAG, "mInputDispatcher rejected the event!");