Fixing up WebComponents types & tests

sdk/lib/html/dartium/html_dartium.dart

Index: sdk/lib/html/dartium/html_dartium.dart
diff --git a/sdk/lib/html/dartium/html_dartium.dart b/sdk/lib/html/dartium/html_dartium.dart
index 0b70951e10e7563d66fb039ca402e7b478d9ba53..055d38bf5d18d478d5bab092e56489a72dee8edb 100644
--- a/sdk/lib/html/dartium/html_dartium.dart
+++ b/sdk/lib/html/dartium/html_dartium.dart
@@ -9160,7 +9160,9 @@ abstract class Element extends Node implements ElementTraversal {
 
 
   /** @domName Element.webkitCreateShadowRoot */
-  ShadowRoot webkitCreateShadowRoot() native "Element_webkitCreateShadowRoot_Callback";
+  @SupportedBrowser(SupportedBrowser.CHROME, '25')
+  @Experimental()
+  ShadowRoot createShadowRoot() native "Element_webkitCreateShadowRoot_Callback";
 
 
   /** @domName Element.webkitMatchesSelector */
@@ -19380,6 +19382,11 @@ class SelectElement extends _Element_Merged {
 class ShadowElement extends _Element_Merged {
   ShadowElement.internal() : super.internal();
 
+  /**
+   * Checks if this type is supported on the current platform
+   */
+  static bool get supported => true;
+
 
   /** @domName HTMLShadowElement.olderShadowRoot */
   ShadowRoot get olderShadowRoot native "HTMLShadowElement_olderShadowRoot_Getter";
@@ -19401,6 +19408,8 @@ class ShadowElement extends _Element_Merged {
 
 
 /// @domName ShadowRoot
+@SupportedBrowser(SupportedBrowser.CHROME, '25')
+@Experimental()
 class ShadowRoot extends DocumentFragment {
   ShadowRoot.internal() : super.internal();