Make <meter> transparent if -webkit-appearance:none or background CSS property is specified.

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

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 11 matching lines @@
 
 #include "core/html/HTMLMeterElement.h"
 
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/HTMLNames.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/frame/UseCounter.h"
+#include "core/html/HTMLContentElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/html/shadow/MeterShadowElement.h"
 #include "core/layout/LayoutMeter.h"
 #include "core/layout/LayoutTheme.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 HTMLMeterElement::HTMLMeterElement(Document& document)
@@ skipping 160 matching lines @@
     RefPtrWillBeRawPtr<MeterInnerElement> inner = MeterInnerElement::create(document());
     root.appendChild(inner);
 
     RefPtrWillBeRawPtr<MeterBarElement> bar = MeterBarElement::create(document());
     m_value = MeterValueElement::create(document());
     m_value->setWidthPercentage(0);
     m_value->updatePseudo();
     bar->appendChild(m_value);
 
     inner->appendChild(bar);
+
+    RefPtrWillBeRawPtr<MeterFallbackElement> fallback = MeterFallbackElement::create(document());
+    fallback->appendChild(HTMLContentElement::create(document()));
+    root.appendChild(fallback.release());
 }
 
 void HTMLMeterElement::willAddFirstAuthorShadowRoot()
 {
     ASSERT(RuntimeEnabledFeatures::authorShadowDOMForAnyElementEnabled());
     lazyReattachIfAttached();
 }
 
 DEFINE_TRACE(HTMLMeterElement)
 {
     visitor->trace(m_value);
     LabelableElement::trace(visitor);
 }
 
 } // namespace