Add CSS parser recovery from errors while parsing @-webkit-keyframes key values.

Source/core/css/CSSParserValues.h

Index: Source/core/css/CSSParserValues.h
diff --git a/Source/core/css/CSSParserValues.h b/Source/core/css/CSSParserValues.h
index 2be7f558671461253e4f96710b586bee80a44742..1b0abbf17b086aae0dd8ae22c5353342abdd82cc 100644
--- a/Source/core/css/CSSParserValues.h
+++ b/Source/core/css/CSSParserValues.h
@@ -116,9 +116,10 @@ struct CSSParserValue {
         CSSParserFunction* function;
     };
     enum {
-        Operator = 0x100000,
-        Function = 0x100001,
-        Q_EMS    = 0x100002
+        Invalid  = 0x100000,

[hayato, 2013/04/17 08:22:56]

I am wondering why we need to set an explicit value to each enum value here. Is
there any code which checks CSSParserValue::unit using bit-wise operation?

Looks like we can remove explicit enum values here.

e.g.
enum {
  Invalid, Operator, Function, Q_EMS
};

+        Operator = 0x100001,
+        Function = 0x100002,
+        Q_EMS    = 0x100003
     };
     int unit;