Remove Style[Non]InheritedVariables::needs_resolution_

Before StyleCascade, we used to store CSSVariableData objects in need
of var()-resolution on ComputedStyle, and the resolve those
CSSVariableData objects "in place". There was also a performance
optimization which utilized flags which told us whether or not there
was any CSSVariableData object in need of resolution somewhere in
Style[Non]InheritedVariables.

The flags can now be removed, since all CSSVariableData objects are
now resolved in StyleCascade _before_ storage on ComputedStyle.

Change-Id: Ia176691bb02f6da4e3eb322b4984acf707654e4f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2372143Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801121}

third_party/blink/renderer/core/style/style_inherited_variables.cc

@@ -13,11 +13,10 @@ bool StyleInheritedVariables::operator==(
   return DataEquivalent(root_, other.root_) && variables_ == other.variables_;
 }
 
-StyleInheritedVariables::StyleInheritedVariables()
-    : root_(nullptr), needs_resolution_(false) {}
+StyleInheritedVariables::StyleInheritedVariables() : root_(nullptr) {}
 
-StyleInheritedVariables::StyleInheritedVariables(StyleInheritedVariables& other)
-    : needs_resolution_(other.needs_resolution_) {
+StyleInheritedVariables::StyleInheritedVariables(
+    StyleInheritedVariables& other) {
   if (!other.root_) {
     root_ = &other;
   } else {

third_party/blink/renderer/core/style/style_inherited_variables.h

@@ -33,14 +33,12 @@ class CORE_EXPORT StyleInheritedVariables
   }
 
   void SetData(const AtomicString& name, scoped_refptr<CSSVariableData> value) {
-    needs_resolution_ =
-        needs_resolution_ || (value && value->NeedsVariableResolution());
+    DCHECK(!value || !value->NeedsVariableResolution());
     variables_.SetData(name, std::move(value));
   }
   StyleVariables::OptionalData GetData(const AtomicString&) const;
 
   void SetValue(const AtomicString& name, const CSSValue* value) {
-    needs_resolution_ = true;
     variables_.SetValue(name, value);
   }
   StyleVariables::OptionalValue GetValue(const AtomicString&) const;
@@ -53,16 +51,12 @@ class CORE_EXPORT StyleInheritedVariables
   const StyleVariables::DataMap& Data() const { return variables_.Data(); }
   const StyleVariables::ValueMap& Values() const { return variables_.Values(); }
 
-  bool NeedsResolution() const { return needs_resolution_; }
-  void ClearNeedsResolution() { needs_resolution_ = false; }
-
  private:
   StyleInheritedVariables();
   StyleInheritedVariables(StyleInheritedVariables& other);
 
   StyleVariables variables_;
   scoped_refptr<StyleInheritedVariables> root_;
-  bool needs_resolution_;
 };
 
 }  // namespace blink

third_party/blink/renderer/core/style/style_non_inherited_variables.h

@@ -37,8 +37,7 @@ class CORE_EXPORT StyleNonInheritedVariables {
   }
 
   void SetData(const AtomicString& name, scoped_refptr<CSSVariableData> value) {
-    needs_resolution_ =
-        needs_resolution_ || (value && value->NeedsVariableResolution());
+    DCHECK(!value || !value->NeedsVariableResolution());
     variables_.SetData(name, std::move(value));
   }
   StyleVariables::OptionalData GetData(const AtomicString& name) const {
@@ -46,7 +45,6 @@ class CORE_EXPORT StyleNonInheritedVariables {
   }
 
   void SetValue(const AtomicString& name, const CSSValue* value) {
-    needs_resolution_ = true;
     variables_.SetValue(name, value);
   }
   StyleVariables::OptionalValue GetValue(const AtomicString& name) const {
@@ -60,12 +58,8 @@ class CORE_EXPORT StyleNonInheritedVariables {
   const StyleVariables::DataMap& Data() const { return variables_.Data(); }
   const StyleVariables::ValueMap& Values() const { return variables_.Values(); }
 
-  bool NeedsResolution() const { return needs_resolution_; }
-  void ClearNeedsResolution() { needs_resolution_ = false; }
-
  private:
   StyleVariables variables_;
-  bool needs_resolution_ = false;
 };
 
 }  // namespace blink