Add support for KeyboardEvent.location attribute

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 0d3eeb4bc9d1f58422b3bf26ad12b879f3848393..d124a672468d92d53a16cbfa7de93db80ac74561 100644
--- a/Source/core/page/UseCounter.cpp
+++ b/Source/core/page/UseCounter.cpp
@@ -644,6 +644,10 @@ String UseCounter::deprecationMessage(Feature feature)
     case CaptureAttributeAsEnum:
         return "Using the 'capture' attribute as an enum is deprecated. Please use it as a boolean and specify the media types that should be accepted in the 'accept' attribute.";
 
+    // Keyboard Event (DOM Level 3)
+    case KeyboardEventKeyLocation:
+        return "'KeyboardEvent.keyLocation'' is deprecated. Please use 'KeyboardEvent.location' instead.";
+
     // Features that aren't deprecated don't have a deprecation message.
     default:
         return String();