Move has_before_or_after_ from CSSLazyParsingState to CSSLazyPropertyParserImpl

This patches moves the bool maintaining state about the prelude of the
block we are parsing (whether or not the prelude include a
::{before,after}) from CSSLazyParsingState to CSLazyPropertyParserImpl.

This is as we have one CSSLazyParsingState per stylesheet, making this 
the incorrect place to maintain the flag. Before this patch if even one 
block in the stylesheet had ::{before,after} we would lazily parse all 
blocks in the stylesheet if the other conditions in 
CSSLazyPropertyparserImpl::parseProperties was met. 

Since each block gets an  instance of the CSSLazyPropertyParser we 
maintain the information there instead. The drawback to this is 
increased memory use. There is a CSSLazyPropertyParser per declaration 
list, so that adds 1 byte of memory for a stylesheet with N deferred lists. 
However N will usually be small as can be seen in histograms 
tracked under Style.TotalLazyRules

Bug: 642722
Change-Id: Ief6272dd2ae24a31479d9f0c072c1562632a49c1
Reviewed-on: https://chromium-review.googlesource.com/686196
Commit-Queue: Darren Shen <shend@chromium.org>
Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Reviewed-by: Rune Lillesveen <rune@opera.com>
Cr-Commit-Position: refs/heads/master@{#504892}

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

@@ -454,7 +454,7 @@ InvalidationSet* RuleFeatureSet::InvalidationSetForSimpleSelector(
   return nullptr;
 }
 
-void RuleFeatureSet::UpdateInvalidationSets(const RuleData& rule_data) {
+void RuleFeatureSet::UpdateInvalidationSets(RuleData& rule_data) {
   // Given a rule, update the descendant invalidation sets for the features
   // found in its selector. The first step is to extract the features from the
   // rightmost compound selector (extractInvalidationSetFeaturesFromCompound).
@@ -479,7 +479,7 @@ void RuleFeatureSet::UpdateInvalidationSets(const RuleData& rule_data) {
     AddFeaturesToInvalidationSet(EnsureNthInvalidationSet(), features);
   if (features.has_before_or_after) {
     if (rule_data.Rule()->LazyParser())
-      rule_data.Rule()->LazyParser()->LazyState()->SetHasBeforeOrAfter();
+      rule_data.Rule()->LazyParser()->SetHasBeforeOrAfter();
     UpdateInvalidationSetsForContentAttribute(
         rule_data.Rule()->ParsedProperties());
   }
@@ -806,7 +806,7 @@ void RuleFeatureSet::AddFeaturesToInvalidationSets(
 }
 
 RuleFeatureSet::SelectorPreMatch RuleFeatureSet::CollectFeaturesFromRuleData(
-    const RuleData& rule_data) {
+    RuleData& rule_data) {
   CHECK(is_alive_);
   FeatureMetadata metadata;
   if (CollectFeaturesFromSelector(rule_data.Selector(), metadata) ==

third_party/WebKit/Source/core/css/RuleFeature.h

@@ -53,7 +53,7 @@ class CORE_EXPORT RuleFeatureSet {
 
   enum SelectorPreMatch { kSelectorNeverMatches, kSelectorMayMatch };
 
-  SelectorPreMatch CollectFeaturesFromRuleData(const RuleData&);
+  SelectorPreMatch CollectFeaturesFromRuleData(RuleData&);
   void UpdateInvalidationSetsForContentAttribute(const StylePropertySet*);
 
   bool UsesFirstLineRules() const { return metadata_.uses_first_line_rules; }
@@ -178,7 +178,7 @@ class CORE_EXPORT RuleFeatureSet {
   DescendantInvalidationSet& EnsureNthInvalidationSet();
   DescendantInvalidationSet& EnsureTypeRuleInvalidationSet();
 
-  void UpdateInvalidationSets(const RuleData&);
+  void UpdateInvalidationSets(RuleData&);
 
   struct InvalidationSetFeatures {
     DISALLOW_NEW();

third_party/WebKit/Source/core/css/StylePropertySet.h

@@ -36,7 +36,6 @@
 namespace blink {
 
 class CSSStyleDeclaration;
-class CSSLazyParsingState;
 class ImmutableStylePropertySet;
 class MutableStylePropertySet;
 class PropertyRegistry;
@@ -166,7 +165,7 @@ class CSSLazyPropertyParser
   CSSLazyPropertyParser() {}
   virtual ~CSSLazyPropertyParser() {}
   virtual StylePropertySet* ParseProperties() = 0;
-  virtual CSSLazyParsingState* LazyState() const = 0;
+  virtual void SetHasBeforeOrAfter() = 0;
 
   DECLARE_VIRTUAL_TRACE();
 };

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

@@ -110,9 +110,7 @@ class CORE_EXPORT StyleRule : public StyleRuleBase {
   const StylePropertySet& Properties() const;
   const StylePropertySet* ParsedProperties() const { return properties_; }
   MutableStylePropertySet& MutableProperties();
-  const CSSLazyPropertyParser* LazyParser() const {
-    return lazy_property_parser_.Get();
-  }
+  CSSLazyPropertyParser* LazyParser() { return lazy_property_parser_.Get(); }
 
   void WrapperAdoptSelectorList(CSSSelectorList selectors) {
     selector_list_ = std::move(selectors);

third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.h

@@ -33,9 +33,6 @@ class CSSLazyParsingState
   // know the total number of style rules that deferred parsing.
   void FinishInitialParsing();
 
-  void SetHasBeforeOrAfter() { has_before_or_after = true; }
-  bool HasBeforeOrAfter() { return has_before_or_after; }
-
   // Helper method used to bump total_style_rules_.
   CSSLazyPropertyParserImpl* CreateLazyParser(const CSSParserTokenRange& block);
 
@@ -90,10 +87,6 @@ class CSSLazyParsingState
 
   int usage_;
 
-  // Used to enable lazy parsing for content attributes inside ::before/::after
-  // blocks
-  bool has_before_or_after = false;
-
   // Whether or not use counting is enabled for parsing. This will usually be
   // true, except for when stylesheets with @imports are removed from the page.
   // See StyleRuleImport::setCSSStyleSheet.

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

@@ -24,8 +24,8 @@ StylePropertySet* CSSLazyPropertyParserImpl::ParseProperties() {
   StylePropertySet* property_set =
       CSSParserImpl::ParseDeclarationListForLazyStyle(tokens_,
                                                       lazy_state_->Context());
-  if (property_set->FindPropertyIndex(CSSPropertyContent) != -1 &&
-      lazy_state_->HasBeforeOrAfter() && lazy_state_->HasRuleSet()) {
+  if (has_before_or_after_ && lazy_state_->HasRuleSet() &&
+      property_set->FindPropertyIndex(CSSPropertyContent) != -1) {
     lazy_state_->GetRuleSet().UpdateInvalidationSetsForContentAttribute(
         property_set);
     lazy_state_->GetStyleEngine().MarkGlobalRuleSetDirty();

third_party/WebKit/Source/core/css/parser/CSSLazyPropertyParserImpl.h

@@ -21,7 +21,7 @@ class CSSLazyPropertyParserImpl : public CSSLazyPropertyParser {
 
   // CSSLazyPropertyParser:
   StylePropertySet* ParseProperties() override;
-  CSSLazyParsingState* LazyState() const override { return lazy_state_.Get(); }
+  void SetHasBeforeOrAfter() override { has_before_or_after_ = true; }
 
   DEFINE_INLINE_TRACE() {
     visitor->Trace(lazy_state_);
@@ -31,6 +31,7 @@ class CSSLazyPropertyParserImpl : public CSSLazyPropertyParser {
  private:
   Vector<CSSParserToken> tokens_;
   Member<CSSLazyParsingState> lazy_state_;
+  bool has_before_or_after_ = false;
 };
 
 }  // namespace blink