Simplify CSS variables resolution logic [1 of 2]

third_party/WebKit/Source/core/css/resolver/CSSVariableResolver.h

 // Copyright 2015 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.
 
 #ifndef CSSVariableResolver_h
 #define CSSVariableResolver_h
 
 #include "core/CSSPropertyNames.h"
 #include "core/css/parser/CSSParserToken.h"
 #include "wtf/HashSet.h"
@@ skipping 12 matching lines @@
     static void resolveVariableDefinitions(StyleVariableData*);
     static void resolveAndApplyVariableReferences(StyleResolverState&, CSSPropertyID, const CSSVariableReferenceValue&);
 
     // Shorthand properties are not supported.
     static PassRefPtrWillBeRawPtr<CSSValue> resolveVariableReferences(StyleVariableData*, CSSPropertyID, const CSSVariableReferenceValue&);
 
 private:
     CSSVariableResolver(StyleVariableData*);
     CSSVariableResolver(StyleVariableData*, AtomicString& variable);
 
-    struct ResolutionState {
-        bool success;
-        // Resolution doesn't finish when a cycle is detected. Fallbacks still
-        // need to be tracked for additional cycles, and invalidation only
-        // applies back to cycle starts. This context member tracks all
-        // detected cycle start points.
-        HashSet<AtomicString> cycleStartPoints;
-
-        ResolutionState()
-            : success(true)
-        { };
-    };
-
-    void resolveFallback(CSSParserTokenRange, Vector<CSSParserToken>& result, ResolutionState& context);
-    void resolveVariableTokensRecursive(CSSParserTokenRange, Vector<CSSParserToken>& result, ResolutionState& context);
-    void resolveVariableReferencesFromTokens(CSSParserTokenRange tokens, Vector<CSSParserToken>& result, ResolutionState& context);
+    // Returns false if we encounter a reference to an invalid variable with no fallback
+    bool resolveFallback(CSSParserTokenRange, Vector<CSSParserToken>& result);
+    bool resolveVariableTokensRecursive(CSSParserTokenRange, Vector<CSSParserToken>& result);
+    bool resolveVariableReferencesFromTokens(CSSParserTokenRange tokens, Vector<CSSParserToken>& result);
 
     StyleVariableData* m_styleVariableData;
     HashSet<AtomicString> m_variablesSeen;
+    // Resolution doesn't finish when a cycle is detected. Fallbacks still
+    // need to be tracked for additional cycles, and invalidation only
+    // applies back to cycle starts.
+    HashSet<AtomicString> m_cycleStartPoints;
 };
 
 } // namespace blink
 
 #endif // CSSVariableResolver