[WebVTT] Support text-decoration-{text,color,style} on CSS ::cue pseudo-element

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 6f544242c4d57bf8edacbec294f2b9fa4197967a..b88b6ace4547a2380c4a46047ea18f0df77af368 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -1151,6 +1151,10 @@ static inline bool isValidCueStyleProperty(CSSPropertyID id)
     case CSSPropertyTextShadow:
     case CSSPropertyBorderStyle:
         return true;
+    case CSSPropertyTextDecorationLine:

[Julien - ping for review, 2013/07/18 01:06:02]

I would include the 'text-decoration' shorthand here too and move them to an
ASSERT_NOT_REACHED case (with the explanation that we expand shorthands at parse
time [except 'font']). This would make it obvious that we allow them but don't
expect any here. Your code is totally right but would make people wonder if
omitting 'text-decoration' is a coding mistake.

+    case CSSPropertyTextDecorationStyle:
+    case CSSPropertyTextDecorationColor:
+        return RuntimeEnabledFeatures::css3TextDecorationsEnabled();
     default:
         break;
     }