Added experimental tilt and tiltDirection to the Touch interface

LayoutTests/fast/events/touch/touch-tilt.html

+<script src="../../../resources/js-test.js"></script> 
+
+<p id="description"></p>
+<div id="console"></div>
+<script type="text/javascript">
+description('Test verifies tilt and tiltDirection can be plumbed through correctly via eventSender');
+
+var touch = null;
+
+document.addEventListener('touchmove', function(event) {
+    shouldBeNull('touch');
+    touch = event.touches.item(0);

[Rick Byers, 2015/03/17 14:38:48]

nit: touches is an array, so access to item 0 is almost always written as
"touches[0]" rather than using the 'item' function.

[d.pikalov, 2015/03/17 16:15:51]

Done.

+}, false);
+
+if (window.eventSender) {
+    eventSender.clearTouchPoints();
+    eventSender.addTouchPoint(100, 100);
+    eventSender.touchStart();
+    touch = null;
+
+    eventSender.updateTouchPoint(0, 110, 110);
+    debug('Sending touchmove (1)');
+    eventSender.touchMove();
+    shouldBeNonNull('touch');
+    shouldBeNaN('touch.tilt');
+    shouldBeNaN('touch.tiltDirection');
+    touch = null;
+
+    eventSender.clearTouchPoints();

[Rick Byers, 2015/03/17 14:38:48]

you should probably call evendSender.touchEnd() here, otherwise I think the
event stream is invalid (the touch went away without ever sending an event
saying it did).  You can probably get away with this today, but we're hoping to
add more validation logic to catch such invalid states.

[d.pikalov, 2015/03/17 16:15:51]

Done.

+    eventSender.addTouchPoint(100, 100);
+    if (eventSender.setTouchPointTilt)
+      eventSender.setTouchPointTilt(0, 10, 10, false);
+    eventSender.touchStart();

[Rick Byers, 2015/03/17 14:38:47]

you should verify the tilt after touchstart too - just add your handler to both
touchmove and touchstart events.

[d.pikalov, 2015/03/17 16:15:51]

Done.

+    touch = null;
+
+    if (eventSender.setTouchPointTilt)
+      eventSender.setTouchPointTilt(0, 45, 60, true);
+    debug('Sending touchmove (2)');
+    eventSender.touchMove();
+    shouldBeNonNull('touch');
+    shouldBe('touch.tilt', '45');
+    shouldBe('touch.tiltDirection', '60');
+    touch = null;
+} else {
+   debug('This test requires --dump-render-tree.');
+}
+
+</script>