Implement ShadowRoot.mode

third_party/WebKit/Source/core/dom/shadow/ShadowRoot.h

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
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@@ skipping 61 matching lines @@
 
     // TODO(kochi): crbug.com/507413 In non-Oilpan, host() may return null during queued
     // event handling (e.g. during execCommand()).
     Element* host() const { return toElement(parentOrShadowHostNode()); }
     ElementShadow* owner() const { return host() ? host()->shadow() : 0; }
 
     ShadowRoot* youngerShadowRoot() const { return prev(); }
 
     ShadowRoot* olderShadowRootForBindings() const;
 
+    String mode() const { return (type() == ShadowRootType::V0 || type() == ShadowRootType::Open) ? "open" : "closed"; };

[kochi, 2016/03/31 06:19:15]

If type() returns ShadowRootType::UserAgent, this returns "closed" ... is it
okay?
As user agent shadow root is not exposed to web, probably it doesn't break the
web,
but we should be clear about the expectation.

I'd suggest you add another layout test, using window.shadowRoot(element) to get
user-agent shadow root from e.g. <input> element.
(see fast/dom/shadow/shadowroot-type.html for example.)

[yuzuchan, 2016/03/31 07:51:07]

Okay, I added a test case for UA shadow root :)

+
     bool isOpenOrV0() const { return type() == ShadowRootType::V0 || type() == ShadowRootType::Open; }
 
     bool isV1() const { return type() == ShadowRootType::Open || type() == ShadowRootType::Closed; }
 
     bool isYoungest() const { return !youngerShadowRoot(); }
     bool isOldest() const { return !olderShadowRoot(); }
 
     void attach(const AttachContext& = AttachContext()) override;
 
     InsertionNotificationRequest insertedInto(ContainerNode*) override;
@@ skipping 88 matching lines @@
     return adjustedFocusedElement();
 }
 
 DEFINE_NODE_TYPE_CASTS(ShadowRoot, isShadowRoot());
 DEFINE_TYPE_CASTS(ShadowRoot, TreeScope, treeScope, treeScope->rootNode().isShadowRoot(), treeScope.rootNode().isShadowRoot());
 DEFINE_TYPE_CASTS(TreeScope, ShadowRoot, shadowRoot, true, true);
 
 } // namespace blink
 
 #endif // ShadowRoot_h