[LazyParseCSS] WIP Implement token discarding

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

Index: third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.cpp b/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.cpp
index ecac1b8441bce38613c39208877c01c42ce4d74e..94fb52a8d7d7eff7b971e091bd4d0c6e4874ea98 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.cpp
@@ -16,14 +16,18 @@ CSSLazyParsingState::CSSLazyParsingState(const CSSParserContext* context,
                                          const String& sheetText,
                                          StyleSheetContents* contents)
     : m_context(context),
-      m_escapedStrings(std::move(escapedStrings)),
       m_sheetText(sheetText),
       m_owningContents(contents),
       m_parsedStyleRules(0),
       m_totalStyleRules(0),
       m_styleRulesNeededForNextMilestone(0),
       m_usage(UsageGe0),
-      m_shouldUseCount(m_context->isUseCounterRecordingEnabled()) {}
+      m_shouldUseCount(m_context->isUseCounterRecordingEnabled()) {
+  m_escapedStrings.reserveCapacityForSize(escapedStrings.size());
+  for (const auto& escapedString : escapedStrings) {
+    m_escapedStrings.insert(escapedString.impl()->bytes(), escapedString);
+  }
+}
 
 void CSSLazyParsingState::finishInitialParsing() {
   recordUsageMetrics();
@@ -89,6 +93,11 @@ bool CSSLazyParsingState::shouldLazilyParseProperties(
   return true;
 }
 
+bool CSSLazyParsingState::tokenBackingUsesEscapedString(
+    const void* tokenBackingBytes) {
+  return m_escapedStrings.contains(tokenBackingBytes);
+}
+
 void CSSLazyParsingState::recordUsageMetrics() {
   DEFINE_STATIC_LOCAL(EnumerationHistogram, usageHistogram,
                       ("Style.LazyUsage.Percent", UsageLastValue));