[LazyParseCSS] WIP Implement token discarding

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

Index: third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.h
diff --git a/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.h b/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.h
index 5b177ca342da14e8a98ea1c7fef2eeed1b048c40..494985acc761d479e2f7211fe3acb82f3ccbf437 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.h
+++ b/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.h
@@ -8,6 +8,7 @@
 #include "core/css/CSSSelectorList.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/css/parser/CSSParserMode.h"
+#include "wtf/HashMap.h"
 #include "wtf/Vector.h"
 #include "wtf/text/WTFString.h"
 
@@ -41,6 +42,8 @@ class CSSLazyParsingState
   bool shouldLazilyParseProperties(const CSSSelectorList&,
                                    const CSSParserTokenRange& block) const;
 
+  bool tokenBackingUsesEscapedString(const void* tokenBackingBytes);
+
   DECLARE_TRACE();
 
   // Exposed for tests. This enum is used to back a histogram, so new values
@@ -62,7 +65,7 @@ class CSSLazyParsingState
   void recordUsageMetrics();
 
   Member<const CSSParserContext> m_context;
-  Vector<String> m_escapedStrings;
+  HashMap<const void*, String> m_escapedStrings;
   // Also referenced on the css resource.
   String m_sheetText;