Bug 1361880 - Prevent toolbar from animating when drag threshold has not been reached r=botond

MozReview-Commit-ID: 14WKMWdjjsf

gfx/layers/apz/src/AndroidDynamicToolbarAnimator.cpp

@@ -579,6 +579,7 @@ AndroidDynamicToolbarAnimator::HandleTouchEnd(StaticToolbarState aCurrentToolbar
   mControllerStartTouch = 0;
   mControllerPreviousTouch = 0;
   mControllerTotalDistance = 0;
+  bool dragThresholdReached = mControllerDragThresholdReached;
   mControllerDragThresholdReached = false;
   mControllerLastEventTimeStamp = 0;
   bool cancelTouchTracking = mControllerCancelTouchTracking;
@@ -595,6 +596,12 @@ AndroidDynamicToolbarAnimator::HandleTouchEnd(StaticToolbarState aCurrentToolbar
     return;
   }
 
+  // The drag threshold has not been reach and the toolbar is either completely visible or completely hidden.
+  if (!dragThresholdReached && ((mControllerToolbarHeight == mControllerMaxToolbarHeight) || (mControllerToolbarHeight == 0))) {
+    ShowToolbarIfNotVisible(aCurrentToolbarState);
+    return;
+  }
+
   // The toolbar is already where it needs to be so just return.
   if (((direction == MOVE_TOOLBAR_DOWN) && (mControllerToolbarHeight == mControllerMaxToolbarHeight)) ||
       ((direction == MOVE_TOOLBAR_UP) && (mControllerToolbarHeight == 0))) {