Add a UA style sheet for predefined counter styles

This patch adds a basic UA style sheet for the 'decimal' and 'disc'
counter styles, and plumbs them into RuleSet. This is in preparation to
implement tree-scoped counter style references.

Bug: 687225
Change-Id: If4effec939a2bfdedc5079e95c4c593f622db652
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2574071Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org>
Commit-Queue: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833915}

third_party/blink/public/blink_resources.grd

@@ -14,6 +14,7 @@
       <include name="IDR_UASTYLE_VIEW_SOURCE_CSS" file="../renderer/core/css/view-source.css" type="BINDATA" compress="gzip"/>
       <include name="IDR_UASTYLE_THEME_CHROMIUM_ANDROID_CSS" file="../renderer/core/html/resources/android.css" type="BINDATA" compress="gzip"/>
       <include name="IDR_UASTYLE_FULLSCREEN_ANDROID_CSS" file="../renderer/core/css/fullscreenAndroid.css" type="BINDATA" compress="gzip"/>
+      <include name="IDR_UASTYLE_PREDEFINED_COUNTER_STYLES_CSS" file="../renderer/core/css/predefined_counter_styles.css" type="BINDATA" compress="gzip"/>
       <include name="IDR_UASTYLE_THEME_CHROMIUM_LINUX_CSS" file="../renderer/core/html/resources/linux.css" type="BINDATA" compress="gzip"/>
       <if expr="is_macosx">
         <include name="IDR_UASTYLE_THEME_MAC_CSS" file="../renderer/core/html/resources/mac.css" type="BINDATA" compress="gzip"/>

third_party/blink/renderer/core/css/css_default_style_sheets.cc

@@ -94,9 +94,16 @@ CSSDefaultStyleSheets::CSSDefaultStyleSheets()
       RuntimeEnabledFeatures::ForcedColorsEnabled()
           ? UncompressResourceAsASCIIString(IDR_UASTYLE_THEME_FORCED_COLORS_CSS)
           : String();
+  // Predefined @counter-style rules
+  String predefined_counter_styles_sheet =
+      RuntimeEnabledFeatures::CSSAtRuleCounterStyleEnabled()
+          ? UncompressResourceAsASCIIString(
+                IDR_UASTYLE_PREDEFINED_COUNTER_STYLES_CSS)
+          : String();
   String default_rules = UncompressResourceAsASCIIString(IDR_UASTYLE_HTML_CSS) +
                          LayoutTheme::GetTheme().ExtraDefaultStyleSheet() +
-                         forced_colors_style_sheet;
+                         forced_colors_style_sheet +
+                         predefined_counter_styles_sheet;
 
   default_style_sheet_ = ParseUASheet(default_rules);
 

third_party/blink/renderer/core/css/parser/css_parser_impl.cc

@@ -945,10 +945,15 @@ StyleRuleCounterStyle* CSSParserImpl::ConsumeCounterStyleRule(
     return nullptr;
 
   if (name_token.GetType() != kIdentToken ||
-      !css_parsing_utils::IsCustomIdent<CSSValueID::kNone, CSSValueID::kDecimal,
-                                        CSSValueID::kDisc>(name_token.Id()))
+      !css_parsing_utils::IsCustomIdent<CSSValueID::kNone>(name_token.Id()))
     return nullptr;
 
+  if (GetContext()->Mode() != kUASheetMode) {
+    if (name_token.Id() == CSSValueID::kDecimal ||
+        name_token.Id() == CSSValueID::kDisc)
+      return nullptr;
+  }
+
   AtomicString name(name_token.Value().ToString());
 
   if (observer_) {

third_party/blink/renderer/core/css/predefined_counter_styles.css

+/*
+ * Copyright 2020 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.
+ */
+
+/* TODO: Add the remaining counter styles */
+
+@counter-style decimal {
+  system: numeric;
+  symbols: '0' '1' '2' '3' '4' '5' '6' '7' '8' '9';
+}
+
+@counter-style disc {
+  system: cyclic;
+  symbols: \2022;
+  suffix: " ";
+}
+

third_party/blink/renderer/core/css/rule_set.cc

@@ -370,6 +370,12 @@ void RuleSet::AddPropertyRule(StyleRuleProperty* rule) {
   property_rules_.push_back(rule);
 }
 
+void RuleSet::AddCounterStyleRule(StyleRuleCounterStyle* rule) {
+  EnsurePendingRules();  // So that counter_style_rules_.ShrinkToFit() gets
+                         // called.
+  counter_style_rules_.push_back(rule);
+}
+
 void RuleSet::AddScrollTimelineRule(StyleRuleScrollTimeline* rule) {
   EnsurePendingRules();  // So that property_rules_.ShrinkToFit() gets called.
   scroll_timeline_rules_.push_back(rule);
@@ -410,6 +416,9 @@ void RuleSet::AddChildRules(const HeapVector<Member<StyleRuleBase>>& rules,
       AddKeyframesRule(keyframes_rule);
     } else if (auto* property_rule = DynamicTo<StyleRuleProperty>(rule)) {
       AddPropertyRule(property_rule);
+    } else if (auto* counter_style_rule =
+                   DynamicTo<StyleRuleCounterStyle>(rule)) {
+      AddCounterStyleRule(counter_style_rule);
     } else if (auto* scroll_timeline_rule =
                    DynamicTo<StyleRuleScrollTimeline>(rule)) {
       AddScrollTimelineRule(scroll_timeline_rule);
@@ -498,6 +507,7 @@ void RuleSet::CompactRules() {
   page_rules_.ShrinkToFit();
   font_face_rules_.ShrinkToFit();
   keyframes_rules_.ShrinkToFit();
+  counter_style_rules_.ShrinkToFit();
   property_rules_.ShrinkToFit();
   deep_combinator_or_shadow_pseudo_rules_.ShrinkToFit();
   part_pseudo_rules_.ShrinkToFit();
@@ -540,6 +550,7 @@ void RuleSet::Trace(Visitor* visitor) const {
   visitor->Trace(font_face_rules_);
   visitor->Trace(keyframes_rules_);
   visitor->Trace(property_rules_);
+  visitor->Trace(counter_style_rules_);
   visitor->Trace(scroll_timeline_rules_);
   visitor->Trace(deep_combinator_or_shadow_pseudo_rules_);
   visitor->Trace(part_pseudo_rules_);

third_party/blink/renderer/core/css/rule_set.h

@@ -29,6 +29,7 @@
 #include "third_party/blink/renderer/core/css/resolver/media_query_result.h"
 #include "third_party/blink/renderer/core/css/rule_feature_set.h"
 #include "third_party/blink/renderer/core/css/style_rule.h"
+#include "third_party/blink/renderer/core/css/style_rule_counter_style.h"
 #include "third_party/blink/renderer/platform/heap/collection_support/heap_linked_stack.h"
 #include "third_party/blink/renderer/platform/wtf/forward.h"
 #include "third_party/blink/renderer/platform/wtf/hash_map.h"
@@ -265,6 +266,9 @@ class CORE_EXPORT RuleSet final : public GarbageCollected<RuleSet> {
   const HeapVector<Member<StyleRuleProperty>>& PropertyRules() const {
     return property_rules_;
   }
+  const HeapVector<Member<StyleRuleCounterStyle>>& CounterStyleRules() const {
+    return counter_style_rules_;
+  }
   const HeapVector<Member<StyleRuleScrollTimeline>>& ScrollTimelineRules()
       const {
     return scroll_timeline_rules_;
@@ -323,6 +327,7 @@ class CORE_EXPORT RuleSet final : public GarbageCollected<RuleSet> {
   void AddKeyframesRule(StyleRuleKeyframes*);
   void AddPropertyRule(StyleRuleProperty*);
   void AddScrollTimelineRule(StyleRuleScrollTimeline*);
+  void AddCounterStyleRule(StyleRuleCounterStyle*);
 
   bool MatchMediaForAddRules(const MediaQueryEvaluator& evaluator,
                              const MediaQuerySet* media_queries);
@@ -371,6 +376,7 @@ class CORE_EXPORT RuleSet final : public GarbageCollected<RuleSet> {
   HeapVector<Member<StyleRuleFontFace>> font_face_rules_;
   HeapVector<Member<StyleRuleKeyframes>> keyframes_rules_;
   HeapVector<Member<StyleRuleProperty>> property_rules_;
+  HeapVector<Member<StyleRuleCounterStyle>> counter_style_rules_;
   HeapVector<Member<StyleRuleScrollTimeline>> scroll_timeline_rules_;
   HeapVector<MinimalRuleData> deep_combinator_or_shadow_pseudo_rules_;
   HeapVector<MinimalRuleData> content_pseudo_element_rules_;

third_party/blink/renderer/core/css/rule_set_test.cc

@@ -30,6 +30,7 @@
 #include "third_party/blink/renderer/core/css/rule_set.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/renderer/core/css/css_default_style_sheets.h"
 #include "third_party/blink/renderer/core/css/css_keyframes_rule.h"
 #include "third_party/blink/renderer/core/css/css_rule_list.h"
 #include "third_party/blink/renderer/core/css/css_test_helpers.h"
@@ -391,4 +392,14 @@ TEST(RuleSetTest, KeyframesRulesVendorPrefixed) {
   EXPECT_FALSE(rule->IsVendorPrefixed());
 }
 
+TEST(RuleSetTest, UACounterStyleRules) {
+  ScopedCSSAtRuleCounterStyleForTest enabled_scope(true);
+
+  RuleSet* default_rule_set = CSSDefaultStyleSheets::Instance().DefaultStyle();
+  ASSERT_TRUE(default_rule_set);
+  ASSERT_FALSE(default_rule_set->CounterStyleRules().IsEmpty());
+
+  EXPECT_EQ("decimal", default_rule_set->CounterStyleRules()[0]->GetName());
+}
+
 }  // namespace blink