METER with -webkit-appearance:none should be rendered with the normal CSS way.

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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #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/NodeComputedStyle.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/frame/UseCounter.h"
+#include "core/html/HTMLContentElement.h"
 #include "core/html/HTMLDivElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/layout/LayoutObject.h"
 #include "core/style/ComputedStyle.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
+// ----------------------------------------------------------------
+
+class MeterFallbackElement final : public HTMLDivElement {
+public:
+    DECLARE_NODE_FACTORY(MeterFallbackElement);
+
+private:
+    explicit MeterFallbackElement(Document& doc)
+        : HTMLDivElement(doc)
+    {
+        setHasCustomStyleCallbacks();
+    }
+
+    PassRefPtr<ComputedStyle> customStyleForLayoutObject() override
+    {
+        // We can't use setInlineStyleProperty() because it updates the DOM
+        // tree.  We shouldn't do it during style calculation.
+        // TODO(tkent): Injecting a CSS variable by host is a better approach?
+        Element* host = shadowHost();
+        RefPtr<ComputedStyle> style = originalStyleForLayoutObject();
+        if (!host || !host->computedStyle() || host->computedStyle()->appearance() != MeterPart || style->display() == NONE)
+            return style.release();
+        RefPtr<ComputedStyle> newStyle = ComputedStyle::clone(*style);
+        newStyle->setDisplay(NONE);
+        newStyle->setUnique();
+        return newStyle.release();
+    }
+};
+
+DEFINE_NODE_FACTORY(MeterFallbackElement)
+
+// ----------------------------------------------------------------
+
+class MeterInnerElement final : public HTMLDivElement {
+public:
+    DECLARE_NODE_FACTORY(MeterInnerElement);
+
+private:
+    explicit MeterInnerElement(Document& doc)
+        : HTMLDivElement(doc)
+    {
+        setHasCustomStyleCallbacks();
+    }
+
+    PassRefPtr<ComputedStyle> customStyleForLayoutObject() override
+    {
+        // We can't use setInlineStyleProperty() because it updates the DOM
+        // tree.  We shouldn't do it during style calculation.
+        // TODO(tkent): Injecting a CSS variable by host is a better approach?
+        Element* host = shadowHost();
+        RefPtr<ComputedStyle> style = originalStyleForLayoutObject();
+        if (!host || !host->computedStyle() || host->computedStyle()->appearance() == MeterPart || style->display() == NONE)
+            return style.release();
+        RefPtr<ComputedStyle> newStyle = ComputedStyle::clone(*style);
+        newStyle->setDisplay(NONE);
+        newStyle->setUnique();
+        return newStyle.release();
+    }
+};
+
+DEFINE_NODE_FACTORY(MeterInnerElement)
+
+// ----------------------------------------------------------------
+
 HTMLMeterElement::HTMLMeterElement(Document& document)
     : LabelableElement(meterTag, document)
 {
     UseCounter::count(document, UseCounter::MeterElement);
 }
 
 HTMLMeterElement::~HTMLMeterElement()
 {
 }
 
@@ skipping 137 matching lines @@
 
 void HTMLMeterElement::didElementStateChange()
 {
     updateValueAppearance(valueRatio() * 100);
 }
 
 void HTMLMeterElement::didAddUserAgentShadowRoot(ShadowRoot& root)
 {
     ASSERT(!m_value);
 
-    HTMLDivElement* inner = HTMLDivElement::create(document());
+    MeterInnerElement* inner = MeterInnerElement::create(document());
     inner->setShadowPseudoId(AtomicString("-webkit-meter-inner-element"));
     root.appendChild(inner);
 
     HTMLDivElement* bar = HTMLDivElement::create(document());
     bar->setShadowPseudoId(AtomicString("-webkit-meter-bar"));
 
     m_value = HTMLDivElement::create(document());
     updateValueAppearance(0);
     bar->appendChild(m_value);
 
     inner->appendChild(bar);
+
+    MeterFallbackElement* fallback = MeterFallbackElement::create(document());
+    fallback->appendChild(HTMLContentElement::create(document()));
+    root.appendChild(fallback);
 }
 
 void HTMLMeterElement::updateValueAppearance(double percentage)
 {
     DEFINE_STATIC_LOCAL(AtomicString, optimumPseudoId, ("-webkit-meter-optimum-value"));
     DEFINE_STATIC_LOCAL(AtomicString, suboptimumPseudoId, ("-webkit-meter-suboptimum-value"));
     DEFINE_STATIC_LOCAL(AtomicString, evenLessGoodPseudoId, ("-webkit-meter-even-less-good-value"));
 
     m_value->setInlineStyleProperty(CSSPropertyWidth, percentage, CSSPrimitiveValue::UnitType::Percentage);
     switch (getGaugeRegion()) {
     case GaugeRegionOptimum:
         m_value->setShadowPseudoId(optimumPseudoId);
         break;
     case GaugeRegionSuboptimal:
         m_value->setShadowPseudoId(suboptimumPseudoId);
         break;
     case GaugeRegionEvenLessGood:
         m_value->setShadowPseudoId(evenLessGoodPseudoId);
         break;
     }
 }
 
+bool HTMLMeterElement::canContainRangeEndPoint() const
+{
+    document().updateLayoutTreeForNode(this);
+    return computedStyle() && !computedStyle()->hasAppearance();
+}
+
 DEFINE_TRACE(HTMLMeterElement)
 {
     visitor->trace(m_value);
     LabelableElement::trace(visitor);
 }
 
 } // namespace blink