If we get TOUCH_UP before getting the WebCore's
response for TOUCH_DOWN, remove the pending TOUCH_EVENT
before proceeding to fling.

This is partial fix for 
http://b/issue?id=2450534
diff --git a/core/java/android/webkit/WebView.java b/core/java/android/webkit/WebView.java
index 9af2d51..6d82797 100644
--- a/core/java/android/webkit/WebView.java
+++ b/core/java/android/webkit/WebView.java
@@ -4441,6 +4441,14 @@
                             if (mFullScreenHolder == null
                                     && (computeHorizontalScrollExtent() < computeHorizontalScrollRange()
                                     || computeVerticalScrollExtent() < computeVerticalScrollRange())) {
+                                // remove the pending TOUCH_EVENT and send a
+                                // cancel
+                                mWebViewCore
+                                        .removeMessages(EventHub.TOUCH_EVENT);
+                                WebViewCore.TouchEventData ted = new WebViewCore.TouchEventData();
+                                ted.mAction = MotionEvent.ACTION_CANCEL;
+                                mWebViewCore.sendMessage(EventHub.TOUCH_EVENT,
+                                        ted);
                                 // we will not rewrite drag code here, but we
                                 // will try fling if it applies.
                                 WebViewCore.pauseUpdate(mWebViewCore);