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

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 2d6eda413a8e54f93f72b62588c6461f41b27af2..5b177ca342da14e8a98ea1c7fef2eeed1b048c40 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.h
+++ b/third_party/WebKit/Source/core/css/parser/CSSLazyParsingState.h
@@ -27,6 +27,10 @@ class CSSLazyParsingState
                       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);