Skip tests of ::shadow and /deep/ under native Shadow DOM

These features have been removed from the only native implementation of Shadow DOM v0 (Chrome).

Author: Steven Orvell

test/unit/custom-style.html

@@ -404,11 +404,17 @@
       });
 
       test('::shadow styles applied', function() {
+        if (Polymer.Settings.useNativeShadow) {
+          this.skip();
+        }
         assertComputed(xFoo.$.bar2, '2px');
         assertComputed(xFoo.$.bar2.$.baz, '3px');
       });
 
       test('/deep/ styles applied', function() {
+        if (Polymer.Settings.useNativeShadow) {
+          this.skip();
+        }
         assertComputed(xFoo.$.bar3, '4px');
         assertComputed(xFoo.$.bar3.$.baz, '5px');
       });

test/unit/preserve-style-include/styling-scoped.html

@@ -213,10 +213,16 @@
   });
 
   test('::shadow selectors', function() {
+    if (Polymer.Settings.useNativeShadow) {
+      this.skip();
+    }
     assertComputed(styled.$.child.$.shadow, '7px');
   });
 
   test('/deep/ selectors', function() {
+    if (Polymer.Settings.useNativeShadow) {
+      this.skip();
+    }
     assertComputed(styled.$.child.$.deep, '8px');
   });