Correctly handle touch events that contain touches not previously reported to blink

Source/core/events/EventPath.cpp

Index: Source/core/events/EventPath.cpp
diff --git a/Source/core/events/EventPath.cpp b/Source/core/events/EventPath.cpp
index be6dba179973eafd1306e342968346c34b6c5ab6..2dcf3e5d72857d512aad536818003dd2a284a1e0 100644
--- a/Source/core/events/EventPath.cpp
+++ b/Source/core/events/EventPath.cpp
@@ -338,6 +338,9 @@ void EventPath::adjustForTouchEvent(Node* node, TouchEvent& touchEvent)
     adjustTouchList(node, touchEvent.targetTouches(), adjustedTargetTouches, treeScopes);
     adjustTouchList(node, touchEvent.changedTouches(), adjustedChangedTouches, treeScopes);
 
+    // FIXME: Why aren't we updating the event at all? We're building up these
+    // adjusted TouchLists and throwing them away!
+

[rjkroege, 2014/05/02 20:33:50]

do the layout tests still pass if you comment them out? :-)

and if you're going to add this, maybe a tracker bug?

[Rick Byers, 2014/05/02 21:24:15]

Ah, it looks like I misunderstood the oilpannery here.  We're keeping pointers
to the TouchLists from the TouchEventContext and then mutating those lists. 
Thanks for challenging me on this.

 #ifndef NDEBUG
     for (size_t i = 0; i < m_treeScopeEventContexts.size(); ++i) {
         TreeScope& treeScope = m_treeScopeEventContexts[i]->treeScope();