Remove UserAgent ShadowRoot + Author ShadowRoot code.

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

Index: third_party/WebKit/Source/core/dom/shadow/ShadowRoot.cpp
diff --git a/third_party/WebKit/Source/core/dom/shadow/ShadowRoot.cpp b/third_party/WebKit/Source/core/dom/shadow/ShadowRoot.cpp
index 1b204033c8bd1438d39c6d504460ad665338afa1..7b302dea055c7cdf3ed24f24817be9e6753adce6 100644
--- a/third_party/WebKit/Source/core/dom/shadow/ShadowRoot.cpp
+++ b/third_party/WebKit/Source/core/dom/shadow/ShadowRoot.cpp
@@ -351,4 +351,23 @@ DEFINE_TRACE(ShadowRoot)
     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