add 'manipulation' support to CSS touch-action parsing.

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

Index: Source/web/tests/data/touch-action-pan.html
diff --git a/Source/web/tests/data/touch-action-pan.html b/Source/web/tests/data/touch-action-pan.html
index b99b97ff19efaeaf67720301fb02884cfc46677b..46e0d34268f825d9cbf02addc0fbe24da32e24be 100644
--- a/Source/web/tests/data/touch-action-pan.html
+++ b/Source/web/tests/data/touch-action-pan.html
@@ -9,6 +9,7 @@
 <div class='ta-panx' expected-action='pan-x'>Simple div with touch-action: pan-x</div>
 <div class='ta-pany' expected-action='pan-y'>Simple div with touch-action: pan-y</div>
 <div class='ta-panxy' expected-action='pan-x-y'>Simple div with touch-action: pan-x pan-y</div>
+<div class='ta-manipulation' expected-action='manipulation'>Simple div with touch-action: manipulation</div>
 
 <div class='ta-none' style='height: 0; margin-bottom: 50px'>
   <div class='ta-panx' expected-action='none'>
@@ -52,4 +53,16 @@
   <div class='scroll ta-pany' expected-action='pan-y'>      
     Touch-action: pan-x is not propagated into overflow-scroll elements
   </div>
+</div>
+
+ <div class='ta-panx'>
+  <div class='ta-manipulation' expected-action='pan-x'>
+    Explicitly setting touch-action: manipulation does nothing to prevent propagation of 'pan-x'
+  </div>
+ </div>
+
+ <div class='ta-manipulation'>
+  <div class='ta-auto' expected-action='manipulation'>
+    Explicitly setting touch-action: auto does nothing to prevent propagation of 'manipulation'
+  </div>
 </div>