Implementation of CSS3 nav-up/down/left/right properties from CSS3 UI.

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 245e2fc3509ad218015a186d8c5d95bd88d81c9c..7b3a815c8a40e2507865641ca3ececc468f9a3f7 100644
--- a/Source/core/page/UseCounter.cpp
+++ b/Source/core/page/UseCounter.cpp
@@ -489,6 +489,10 @@ static int mapCSSPropertyIdToCSSSampleId(int id)
     case CSSPropertyMixBlendMode: return 420;
     case CSSPropertyTouchAction: return 421;
     case CSSPropertyGridArea: return 422;
+    case CSSPropertyNavDown: return 423;
+    case CSSPropertyNavLeft: return 424;
+    case CSSPropertyNavRight: return 425;
+    case CSSPropertyNavUp: return 426;
 
     // Add new features above this line (don't change the assigned numbers of the existing
     // items) and update maximumCSSSampleId() with the new maximum value.
@@ -503,7 +507,7 @@ static int mapCSSPropertyIdToCSSSampleId(int id)
     return 0;
 }
 
-static int maximumCSSSampleId() { return 422; }
+static int maximumCSSSampleId() { return 426; }
 
 UseCounter::UseCounter()
 {