Revert of HTMLPlugInElement: Use custom focus logic only when there is a plugin.

Source/core/html/HTMLPlugInElement.cpp

Index: Source/core/html/HTMLPlugInElement.cpp
diff --git a/Source/core/html/HTMLPlugInElement.cpp b/Source/core/html/HTMLPlugInElement.cpp
index df9adf0dd428c3df409379793762ff59bcca331f..5f5dd4f0eeab0b089444ad2e45ad77b2df31c1d0 100644
--- a/Source/core/html/HTMLPlugInElement.cpp
+++ b/Source/core/html/HTMLPlugInElement.cpp
@@ -390,18 +390,14 @@
 
 bool HTMLPlugInElement::isKeyboardFocusable() const
 {
-    if (useFallbackContent() || usePlaceholderContent())
-        return HTMLElement::isKeyboardFocusable();
-
     if (!document().isActive())
         return false;
-
     return pluginWidget() && pluginWidget()->isPluginView() && toPluginView(pluginWidget())->supportsKeyboardFocus();
 }
 
 bool HTMLPlugInElement::hasCustomFocusLogic() const
 {
-    return renderer() && renderer()->isEmbeddedObject();
+    return !hasAuthorShadowRoot();
 }
 
 bool HTMLPlugInElement::isPluginElement() const