Re-attach renderer for progress/meter when author shadow is allowed.

Source/core/html/HTMLProgressElement.cpp

Index: Source/core/html/HTMLProgressElement.cpp
diff --git a/Source/core/html/HTMLProgressElement.cpp b/Source/core/html/HTMLProgressElement.cpp
index 5cb56b1376c9784e47cced32b98081b07b8d533b..617de1b2617719a9c95c593ab733d62a63c13f16 100644
--- a/Source/core/html/HTMLProgressElement.cpp
+++ b/Source/core/html/HTMLProgressElement.cpp
@@ -170,6 +170,12 @@ bool HTMLProgressElement::shouldAppearIndeterminate() const
     return !isDeterminate();
 }
 
+void HTMLProgressElement::willAddFirstAuthorShadowRoot()
+{
+    ASSERT(RuntimeEnabledFeatures::authorShadowDOMForAnyElementEnabled());
+    lazyReattachIfAttached();
+}
+
 void HTMLProgressElement::trace(Visitor* visitor)
 {
     visitor->trace(m_value);