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 5f5dd4f0eeab0b089444ad2e45ad77b2df31c1d0..df9adf0dd428c3df409379793762ff59bcca331f 100644
--- a/Source/core/html/HTMLPlugInElement.cpp
+++ b/Source/core/html/HTMLPlugInElement.cpp
@@ -390,14 +390,18 @@ RenderPart* HTMLPlugInElement::renderPartForJSBindings() const
 
 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 !hasAuthorShadowRoot();
+    return renderer() && renderer()->isEmbeddedObject();
 }
 
 bool HTMLPlugInElement::isPluginElement() const