Remove UserAgent ShadowRoot + Author ShadowRoot code.

third_party/WebKit/Source/core/html/HTMLPlugInElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLPlugInElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLPlugInElement.cpp b/third_party/WebKit/Source/core/html/HTMLPlugInElement.cpp
index 1da1e93109033462b7d7b84b131ae44c13d6fbdd..9c3e5a948a0cb28dd1e21f5d12af8e3e60db8419 100644
--- a/third_party/WebKit/Source/core/html/HTMLPlugInElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLPlugInElement.cpp
@@ -586,11 +586,6 @@ void HTMLPlugInElement::didAddUserAgentShadowRoot(ShadowRoot&)
     userAgentShadowRoot()->appendChild(HTMLContentElement::create(document()));
 }
 
-void HTMLPlugInElement::willAddFirstAuthorShadowRoot()
-{
-    lazyReattachIfAttached();
-}
-
 bool HTMLPlugInElement::hasFallbackContent() const
 {
     return false;
@@ -598,7 +593,7 @@ bool HTMLPlugInElement::hasFallbackContent() const
 
 bool HTMLPlugInElement::useFallbackContent() const
 {
-    return openShadowRoot();
+    return false;
 }
 
 void HTMLPlugInElement::lazyReattachIfNeeded()