[test] lazily parse css style rules

third_party/WebKit/Source/core/css/StyleRule.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2005, 2006, 2008, 2012 Apple Inc. All rights reserved.
  *
  * 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.
  *
@@ skipping 15 matching lines @@
 #include "core/css/CSSKeyframesRule.h"
 #include "core/css/CSSMediaRule.h"
 #include "core/css/CSSNamespaceRule.h"
 #include "core/css/CSSPageRule.h"
 #include "core/css/CSSStyleRule.h"
 #include "core/css/CSSSupportsRule.h"
 #include "core/css/CSSViewportRule.h"
 #include "core/css/StyleRuleImport.h"
 #include "core/css/StyleRuleKeyframe.h"
 #include "core/css/StyleRuleNamespace.h"
+#include "core/css/parser/CSSParserImpl.h"
 
 namespace blink {
 
 struct SameSizeAsStyleRuleBase : public GarbageCollectedFinalized<SameSizeAsStyleRuleBase> {
     unsigned bitfields;
 };
 
 static_assert(sizeof(StyleRuleBase) <= sizeof(SameSizeAsStyleRuleBase), "StyleRuleBase should stay small");
 
 CSSRule* StyleRuleBase::createCSSOMWrapper(CSSStyleSheet* parentSheet) const
@@ skipping 164 matching lines @@
     return sizeof(StyleRule) + sizeof(CSSSelector) + StylePropertySet::averageSizeInBytes();
 }
 
 StyleRule::StyleRule(CSSSelectorList selectorList, StylePropertySet* properties)
     : StyleRuleBase(Style)
     , m_properties(properties)
 {
     m_selectorList = std::move(selectorList);
 }
 
+const StylePropertySet& StyleRule::properties() const
+{
+    if (!m_properties) {
+        m_properties = CSSParserImpl::parseDeclarationListForLazyStyle(m_lazyTokens, *m_context);
+        m_lazyTokens.clear();
+    }
+    return *m_properties;
+}
+
+StyleRule::StyleRule(CSSSelectorList selectorList, CSSParserTokenRange block, const CSSParserContext* context)
+    : StyleRuleBase(Style)
+    , m_selectorList(std::move(selectorList))
+    , m_properties(nullptr)
+    , m_context(context)
+{
+    while (!block.atEnd()) {
+        m_lazyTokens.append(block.consume());
+    }
+}
+
 StyleRule::StyleRule(const StyleRule& o)
     : StyleRuleBase(o)
-    , m_properties(o.m_properties->mutableCopy())
     , m_selectorList(o.m_selectorList.copy())
+    , m_properties(o.properties().mutableCopy())
 {
 }
 
 StyleRule::~StyleRule()
 {
 }
 
 MutableStylePropertySet& StyleRule::mutableProperties()
 {
-    if (!m_properties->isMutable())
-        m_properties = m_properties->mutableCopy();
+    const StylePropertySet& props = properties();
+    if (!props.isMutable())
+        m_properties = props.mutableCopy();
     return *toMutableStylePropertySet(m_properties.get());
 }
 
 DEFINE_TRACE_AFTER_DISPATCH(StyleRule)
 {
     visitor->trace(m_properties);
     StyleRuleBase::traceAfterDispatch(visitor);
 }
 
 StyleRulePage::StyleRulePage(CSSSelectorList selectorList, StylePropertySet* properties)
@@ skipping 142 matching lines @@
     return *toMutableStylePropertySet(m_properties);
 }
 
 DEFINE_TRACE_AFTER_DISPATCH(StyleRuleViewport)
 {
     visitor->trace(m_properties);
     StyleRuleBase::traceAfterDispatch(visitor);
 }
 
 } // namespace blink