Add a WebDocument::watchCssSelectors(selectors)

Source/core/page/UseCounter.cpp

Index: Source/core/page/UseCounter.cpp
diff --git a/Source/core/page/UseCounter.cpp b/Source/core/page/UseCounter.cpp
index 5ec1faa4cfd023c6fc306381c649f91ab15d18bb..4d14ecd969c80311d6a46534717a1959172395f0 100644
--- a/Source/core/page/UseCounter.cpp
+++ b/Source/core/page/UseCounter.cpp
@@ -488,6 +488,7 @@ static int mapCSSPropertyIdToCSSSampleId(int id)
     case CSSPropertyMixBlendMode: return 420;
     case CSSPropertyTouchAction: return 421;
     case CSSPropertyGridArea: return 422;
+    case CSSPropertyInternalCallback: return 423;
 
     // Add new features above this line (don't change the assigned numbers of the existing
     // items) and update maximumCSSSampleId() with the new maximum value.
@@ -502,7 +503,7 @@ static int mapCSSPropertyIdToCSSSampleId(int id)
     return 0;
 }
 
-static int maximumCSSSampleId() { return 422; }
+static int maximumCSSSampleId() { return 423; }
 
 UseCounter::UseCounter()
 {