Merge changes I347b2c80,I9e3185de

* changes:
  Cherry pick of WebKit.org revision r58323. Improves documentation for the TouchStationary handler after discussions in webkit bug 37609.
  Removing the TouchStationary state from PlatformTouchPoint resulted in unforseen build problems upstream at webkit.org so it was reverted.

1 files changed, 7 insertions, 0 deletions

diff --git a/WebCore/page/EventHandler.cpp b/WebCore/page/EventHandler.cpp
index 6082cfe..741401c 100644
--- a/WebCore/page/EventHandler.cpp
+++ b/WebCore/page/EventHandler.cpp
@@ -2622,6 +2622,13 @@ bool EventHandler::handleTouchEvent(const PlatformTouchEvent& event)
             touches->append(touch);
 
         // Now build up the correct list for changedTouches.
+        // Note that  any touches that are in the TouchStationary state (e.g. if
+        // the user had several points touched but did not move them all) should
+        // only be present in the touches list. They may also be added to the
+        // targetTouches list later, but should never be in the changedTouches
+        // list so we do not handle them explicitly here.
+        // See https://bugs.webkit.org/show_bug.cgi?id=37609 for further discussion
+        // about the TouchStationary state.
         if (point.state() == PlatformTouchPoint::TouchReleased)
             releasedTouches->append(touch);
         else if (point.state() == PlatformTouchPoint::TouchCancelled)