Patch overlay panel event stream internally

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/eventfilter/OverlayPanelEventFilter.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.compositor.layouts.eventfilter;
 
 import android.content.Context;
 import android.view.GestureDetector;
 import android.view.MotionEvent;
 import android.view.ViewConfiguration;
@@ skipping 92 matching lines @@
 
     /** The Y coordinate of the synthetic ACTION_DOWN MotionEvent. */
     private float mSyntheticActionDownY;
 
     /** The list of recorded events. */
     private final ArrayList<MotionEvent> mRecordedEvents = new ArrayList<MotionEvent>();
 
     /** The initial Y position of the current gesture. */
     private float mInitialEventY;
 
+    /** Whether or not the superclass has seen a down event. */
+    private boolean mFilterHadDownEvent;
+
     private class SwipeRecognizerImpl extends SwipeRecognizer {
         public SwipeRecognizerImpl(Context context) {
             super(context);
             setSwipeHandler(mPanel);
         }
 
         @Override
         public boolean onSingleTapUp(MotionEvent event) {
             mPanel.handleClick(event.getEventTime(), event.getX() * mPxToDp,
                     event.getY() * mPxToDp);
@@ skipping 198 matching lines @@
         e.recycle();
     }
 
     /**
      * Propagates the given {@link MotionEvent} to the given {@link EventTarget}.
      * @param e The {@link MotionEvent} to be propagated.
      * @param target The {@link EventTarget} to propagate events to.
      */
     private void propagateEvent(MotionEvent e, EventTarget target) {
         if (target == EventTarget.PANEL) {
+            // Make sure the internal gesture detector has seen at least on down event.
+            if (e.getActionMasked() == MotionEvent.ACTION_DOWN) mFilterHadDownEvent = true;
+            if (!mFilterHadDownEvent) {
+                MotionEvent down = MotionEvent.obtain(e);
+                down.setAction(MotionEvent.ACTION_DOWN);
+                super.onTouchEventInternal(down);
+                mFilterHadDownEvent = true;
+            }
             super.onTouchEventInternal(e);
         } else if (target == EventTarget.CONTENT_VIEW) {
             propagateEventToContentViewCore(e);
         }
     }
 
     /**
      * Propagates the given {@link MotionEvent} to the {@link ContentViewCore}.
      * @param e The {@link MotionEvent} to be propagated.
      */
@@ skipping 217 matching lines @@
         public boolean onSingleTapUp(MotionEvent e) {
             return handleSingleTapUp(e);
         }
 
         @Override
         public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
             return handleScroll(e1, e2, distanceY);
         }
     }
 }