Added experimental tilt and tiltDirection to the Touch interface

Source/web/WebInputEventConversion.cpp

Index: Source/web/WebInputEventConversion.cpp
diff --git a/Source/web/WebInputEventConversion.cpp b/Source/web/WebInputEventConversion.cpp
index afe7abfce22041ba349fd2e6aff2930b55794b35..2317b798c2d5b8beb64c4c8f50d2572c8c131e81 100644
--- a/Source/web/WebInputEventConversion.cpp
+++ b/Source/web/WebInputEventConversion.cpp
@@ -437,6 +437,8 @@ PlatformTouchPointBuilder::PlatformTouchPointBuilder(Widget* widget, const WebTo
     m_radius = scaleSizeToWindow(widget, FloatSize(point.radiusX, point.radiusY));
     m_rotationAngle = point.rotationAngle;
     m_force = point.force;
+    m_tilt = point.tilt;
+    m_tiltDirection = point.tiltDirection;

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

Your spec should clarify whether this is intended to take transforms into
account.  Eg. I assume the '0X' axis is relative to current screen rotation. 
But it's physical screen orientation it's relative to, not the co-ordinate
system of the input co-ordinates, right?  Eg. what if I'm receiving the events
inside of an iframe whcih is being spun with a rotation transform.

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

Right, I updated spec with "...angle in relation to the 0X axis of the current
screen orientation..."

 }
 
 PlatformTouchEventBuilder::PlatformTouchEventBuilder(Widget* widget, const WebTouchEvent& event)