Use count strings as keyframes/animation-name identifiers

Source/core/css/parser/CSSGrammar.y

 %{
 
 /*
  *  Copyright (C) 2002-2003 Lars Knoll (knoll@kde.org)
  *  Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *  Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *  Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  *  Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
@@ skipping 21 matching lines @@
 #include "core/css/parser/BisonCSSParser.h"
 #include "core/css/parser/CSSParserMode.h"
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/CSSSelector.h"
 #include "core/css/CSSSelectorList.h"
 #include "core/css/MediaList.h"
 #include "core/css/MediaQueryExp.h"
 #include "core/css/StyleRule.h"
 #include "core/css/StyleSheetContents.h"
 #include "core/dom/Document.h"
+#include "core/frame/UseCounter.h"
 #include "wtf/FastMalloc.h"
 #include <stdlib.h>
 #include <string.h>
 
 using namespace blink;
 using namespace HTMLNames;
 
 #define YYMALLOC fastMalloc
 #define YYFREE fastFree
 
@@ skipping 803 matching lines @@
     ;
 
 keyframes:
     keyframes_rule_start keyframe_name at_rule_header_end_maybe_space '{' at_rule_body_start maybe_space location_label keyframes_rule closing_brace {
         $$ = parser->createKeyframesRule($2, parser->sinkFloatingKeyframeVector($8), $1 /* isPrefixed */);
     }
     ;
 
 keyframe_name:
     IDENT
-    | STRING
+    | STRING {
+        parser->m_context.useCounter()->count(UseCounter::QuotedKeyframesRule);
+    }
     ;
 
 keyframes_rule:
     keyframe_rule_list
     | keyframe_rule_list keyframes_error_recovery {
         parser->clearProperties();
     };
 
 keyframe_rule_list:
     /* empty */ {
@@ skipping 980 matching lines @@
     ;
 
 rule_error_recovery:
     /* empty */
   | rule_error_recovery error
   | rule_error_recovery invalid_square_brackets_block
   | rule_error_recovery invalid_parentheses_block
     ;
 
 %%