Fix movementX/Y attributes for touch pointer events

third_party/WebKit/public/platform/WebPointerProperties.h

Index: third_party/WebKit/public/platform/WebPointerProperties.h
diff --git a/third_party/WebKit/public/platform/WebPointerProperties.h b/third_party/WebKit/public/platform/WebPointerProperties.h
index 27e59c44268912ee535ebd983ab9dc7d7fe9c4bf..49a142e785cafeab892aff39b4c180a9edd36d40 100644
--- a/third_party/WebKit/public/platform/WebPointerProperties.h
+++ b/third_party/WebKit/public/platform/WebPointerProperties.h
@@ -82,6 +82,9 @@ class WebPointerProperties {
 
   Button button;
   PointerType pointerType;
+
+  int movementX;

[Rick Byers, 2017/02/06 22:00:53]

nit: add a comment saying what co-ordinate space this is in

[Navid Zolghadr, 2017/02/07 15:58:51]

I'm not sure there is any answer for this. Dave added a m_frameScale variable in
WebInputEvent which scales this coordinates in movementInRootFrame function
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/WebMo....
I added the same in WebTouchEvent in this CL.

So these will be transformed when they get to blink. So I believe they will have
different meaning? Also I don't know what different coordinate spaces are called
before or after transformations.

[Rick Byers, 2017/02/08 21:45:14]

Ugh, right.  That makes it hard to reason about all these co-ordinates
(movementX/Y is the least of our potential confusion here).  Ok ignore this for
now.  Maybe later we can add some comments better describing the co-ordinate
system for all of the WebTouchEvent/WebMouseEvent co-ordinates.  FWIW the
official documentation is here:
https://www.chromium.org/developers/design-documents/blink-coordinate-spaces

+  int movementY;
 };
 
 }  // namespace blink