Remove UserAgent ShadowRoot + Author ShadowRoot code.

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

 /*
  * 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.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 333 matching lines @@
 DEFINE_TRACE(ShadowRoot)
 {
     visitor->trace(m_prev);
     visitor->trace(m_next);
     visitor->trace(m_shadowRootRareData);
     visitor->trace(m_slotAssignment);
     TreeScope::trace(visitor);
     DocumentFragment::trace(visitor);
 }
 
+std::ostream& operator<<(std::ostream& ostream, const ShadowRootType& type)

[kochi, 2016/04/20 08:21:07]

Can this be compiled in only when DCHECK() is enabled?

[tkent, 2016/04/20 08:31:05]

Yes.  Done.  Release build doesn't need this function for now.

If we use EXPECT_EQ(ShadowRootType::Open, ...) in unit tests, we need this
function even in Release build.

+{
+    switch (type) {
+    case ShadowRootType::UserAgent:
+        ostream << "ShadowRootType::UserAgent";
+        break;
+    case ShadowRootType::V0:
+        ostream << "ShadowRootType::V0";
+        break;
+    case ShadowRootType::Open:
+        ostream << "ShadowRootType::Open";
+        break;
+    case ShadowRootType::Closed:
+        ostream << "ShadowRootType::Closed";
+        break;
+    }
+    return ostream;
+}
+
 } // namespace blink