Current work-in-progress crbug.com/567021

third_party/WebKit/Source/core/css/parser/CSSParserImpl.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/parser/CSSParserImpl.h"
 
 #include "core/css/CSSCustomIdentValue.h"
 #include "core/css/CSSCustomPropertyDeclaration.h"
 #include "core/css/CSSKeyframesRule.h"
 #include "core/css/CSSStyleSheet.h"
@@ skipping 536 matching lines @@
         return nullptr; // Parser error; @viewport prelude should be empty
 
     if (m_observerWrapper) {
         unsigned endOffset = m_observerWrapper->endOffset(prelude);
         m_observerWrapper->observer().startRuleHeader(StyleRule::Viewport, m_observerWrapper->startOffset(prelude));
         m_observerWrapper->observer().endRuleHeader(endOffset);
         m_observerWrapper->observer().startRuleBody(endOffset);
         m_observerWrapper->observer().endRuleBody(endOffset);
     }
 
+    if (m_styleSheet)
+        m_styleSheet->setHasViewportRule();
+
     consumeDeclarationList(block, StyleRule::Viewport);
     return StyleRuleViewport::create(createStylePropertySet(m_parsedProperties, CSSViewportRuleMode));
 }
 
 StyleRuleFontFace* CSSParserImpl::consumeFontFaceRule(CSSParserTokenRange prelude, CSSParserTokenRange block)
 {
     prelude.consumeWhitespace();
     if (!prelude.atEnd())
         return nullptr; // Parse error; @font-face prelude should be empty
 
     if (m_observerWrapper) {
         unsigned endOffset = m_observerWrapper->endOffset(prelude);
         m_observerWrapper->observer().startRuleHeader(StyleRule::FontFace, m_observerWrapper->startOffset(prelude));
         m_observerWrapper->observer().endRuleHeader(endOffset);
         m_observerWrapper->observer().startRuleBody(endOffset);
         m_observerWrapper->observer().endRuleBody(endOffset);
     }
 
     if (m_styleSheet)
-        m_styleSheet->setHasFontFaceRule(true);
+        m_styleSheet->setHasFontFaceRule();
 
     consumeDeclarationList(block, StyleRule::FontFace);
     return StyleRuleFontFace::create(createStylePropertySet(m_parsedProperties, m_context.mode()));
 }
 
 StyleRuleKeyframes* CSSParserImpl::consumeKeyframesRule(bool webkitPrefixed, CSSParserTokenRange prelude, CSSParserTokenRange block)
 {
     prelude.consumeWhitespace();
     CSSParserTokenRange rangeCopy = prelude; // For inspector callbacks
     const CSSParserToken& nameToken = prelude.consumeIncludingWhitespace();
@@ skipping 231 matching lines @@
         else
             return nullptr; // Parser error, invalid value in keyframe selector
         if (range.atEnd())
             return result;
         if (range.consume().type() != CommaToken)
             return nullptr; // Parser error
     }
 }
 
 } // namespace blink