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 7737be9df79c204a9bf22309cb488b98da1f89b0..745bcbf4d147b3a9b4841f2f27f4b172565b0b77 100644
--- a/Source/core/page/UseCounter.cpp
+++ b/Source/core/page/UseCounter.cpp
@@ -485,6 +485,7 @@ int UseCounter::mapCSSPropertyIdToCSSSampleIdForHistogram(int id)
     case CSSPropertyTouchAction: return 421;
     case CSSPropertyGridArea: return 422;
     case CSSPropertyGridTemplate: return 423;
+    case CSSPropertyInternalCallback: return 424;
 
     // Add new features above this line (don't change the assigned numbers of the existing
     // items) and update maximumCSSSampleId() with the new maximum value.
@@ -499,7 +500,7 @@ int UseCounter::mapCSSPropertyIdToCSSSampleIdForHistogram(int id)
     return 0;
 }
 
-static int maximumCSSSampleId() { return 423; }
+static int maximumCSSSampleId() { return 424; }
 
 UseCounter::UseCounter()
 {