Implement touch-action pan-x/pan-y handling on the main thread

Source/web/tests/data/touch-action-overflow.html

Index: Source/web/tests/data/touch-action-overflow.html
diff --git a/Source/web/tests/data/touch-action-overflow.html b/Source/web/tests/data/touch-action-overflow.html
old mode 100644
new mode 100755
index 525aade4a579726e6a61abeda17d3c69a150626f..f415147381b3aa081eda6a2180ed46a1f5fcc701
--- a/Source/web/tests/data/touch-action-overflow.html
+++ b/Source/web/tests/data/touch-action-overflow.html
@@ -24,3 +24,16 @@
     Touch-action: none is not propagated into overflow-scroll elements
   </div>
 </div>
+
+<div class='scroll ta-panx' style='height:75px'>

[Rick Byers, 2013/12/12 20:47:24]

These two tests really test the same code paths as tests in 'simple' (just
intersecting pan-x with auto or pan-y).  I think the key thing to test here is
that the scroller behaves as a boundary for the pan values (not just for 'none'
as tested above).  So for example, have an outer div with ta-panx and a scroller
with ta-pany.  One case like that is probably sufficient since there really
isn't distinct code paths involved here.

[gnana, 2013/12/13 16:52:53]

Done.

+  <div class='ta-auto' expected-action='pan-x'>
+    Touch-action: auto does nothing to prevent propagation of pan-x
+  </div>
+</div>
+
+<div class='scroll ta-panx' style='height:75px'>
+  <div class='ta-pany' expected-action='none'>
+    Explicitly setting touch-action: pan-y does nothing to prevent propagation of pan-x resulting to none
+  </div>
+</div>
+