[LazyParseCSS] Add metrics for total # of rules at 0% and 100% usage

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

 // Copyright 2016 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 CSSLazyParsingState_h
 #define CSSLazyParsingState_h
 
 #include "core/css/CSSSelectorList.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/css/parser/CSSParserMode.h"
 #include "wtf/Vector.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class CSSLazyPropertyParserImpl;
 class CSSParserTokenRange;
 
 // This class helps lazy parsing by retaining necessary state. It should not
 // outlive the StyleSheetContents that initiated the parse, as it retains a raw
 // reference to the UseCounter associated with the style sheet.
 class CSSLazyParsingState
     : public GarbageCollectedFinalized<CSSLazyParsingState> {
  public:
   CSSLazyParsingState(const CSSParserContext*,
                       Vector<String> escapedStrings,
                       const String& sheetText,
                       StyleSheetContents*);
 
+  // Called when all lazy property parsers are initialized. At this point we
+  // know the total number of style rules that deferred parsing.
+  void finishInitialParsing();
+
   // Helper method used to bump m_totalStyleRules.
   CSSLazyPropertyParserImpl* createLazyParser(const CSSParserTokenRange& block);
 
   const CSSParserContext* context();
 
   void countRuleParsed();
 
   bool shouldLazilyParseProperties(const CSSSelectorList&,
                                    const CSSParserTokenRange& block) const;
 
@@ skipping 40 matching lines @@
 
   // Whether or not use counting is enabled for parsing. This will usually be
   // true, except for when stylesheets with @imports are removed from the page.
   // See StyleRuleImport::setCSSStyleSheet.
   const bool m_shouldUseCount;
 };
 
 }  // namespace blink
 
 #endif  // CSSLazyParsingState_h