Added experimental tilt and tiltDirection to the Touch interface

Source/core/dom/Document.idl

 /*
  * Copyright (C) 2006, 2007, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006, 2007 Samuel Weinig <sam@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 173 matching lines @@
     [RuntimeEnabled=Touch] Touch createTouch([Default=Undefined] optional Window window,
                                              [Default=Undefined] optional EventTarget target,
                                              [Default=Undefined] optional long identifier,
                                              [Default=Undefined] optional double pageX,
                                              [Default=Undefined] optional double pageY,
                                              [Default=Undefined] optional double screenX,
                                              [Default=Undefined] optional double screenY,
                                              [Default=Undefined] optional double webkitRadiusX,
                                              [Default=Undefined] optional double webkitRadiusY,
                                              [Default=Undefined] optional float webkitRotationAngle,
-                                             [Default=Undefined] optional float webkitForce);
+                                             [Default=Undefined] optional float webkitForce,
+                                             [Default=Undefined] optional float webkitTilt,

[Rick Byers, 2015/02/13 08:48:05]

remove webkit prefix - that's legacy.  In fact only 'webkitRotationAngle' is
still only available by a prefix (so webkitForce/radius* could also have the
prefix removed if you like).

[d.pikalov, 2015/02/13 13:31:17]

Also, we have to remove those webkit-prefixed properties in Touch.idl, right ?

+                                             [Default=Undefined] optional float webkitTiltDirection);
     [RuntimeEnabled=Touch] TouchList createTouchList(Touch... touches);
 
     [CallWith=ScriptState, CustomElementCallbacks, RaisesException, MeasureAs=DocumentRegisterElement] CustomElementConstructor registerElement(DOMString name, optional ElementRegistrationOptions options);
     [CustomElementCallbacks, PerWorldBindings, RaisesException] Element createElement(DOMString localName, DOMString? typeExtension);
     [CustomElementCallbacks, RaisesException] Element createElementNS(DOMString? namespaceURI, DOMString qualifiedName, DOMString? typeExtension);
 
     // Page visibility API.
     readonly attribute VisibilityState visibilityState;
     readonly attribute boolean hidden;
 
     // Deprecated prefixed page visibility API.
     // TODO(davidben): This is a property so attaching a deprecation warning results in false positives when outputting
     // document in the console. It's possible http://crbug.com/43394 will resolve this.
     [MeasureAs=PrefixedPageVisibility, ImplementedAs=visibilityState] readonly attribute DOMString webkitVisibilityState;
     [MeasureAs=PrefixedPageVisibility, ImplementedAs=hidden] readonly attribute boolean webkitHidden;
 
     readonly attribute HTMLScriptElement currentScript;
 };
 
 Document implements GlobalEventHandlers;
 Document implements ParentNode;