Add WebPointerProperties type.

Source/web/WebInputEvent.cpp

Index: Source/web/WebInputEvent.cpp
diff --git a/Source/web/WebInputEvent.cpp b/Source/web/WebInputEvent.cpp
index dc2a0fe512f90f7d4aaa2fea1d2ea2f0c75d53d4..49514b487934d754da7bab33c1c7587cd4c0a608 100644
--- a/Source/web/WebInputEvent.cpp
+++ b/Source/web/WebInputEvent.cpp
@@ -48,6 +48,7 @@ struct SameSizeAsWebKeyboardEvent : public SameSizeAsWebInputEvent {
 
 struct SameSizeAsWebMouseEvent : public SameSizeAsWebInputEvent {
     int mouseData[10];

[bokan, 2015/07/13 18:45:18]

Actually, shouldn't this have shrunk? Since you removed the 'button' field?

[USE eero AT chromium.org, 2015/07/14 23:44:13]

Yes, mouseData size should be 9 ints, mousePropertiesData size should be 1 int
and pointerPropertiesData size should be 4 ints. But let's just merge all of
them together.

+    int pointerPropertiesData[4];

[Rick Byers, 2015/07/09 00:50:23]

nit: I think it's preferable to just add 4 to the above.  We don't care here
where the size comes from, just the absolute value.

[bokan, 2015/07/13 18:42:22]

Agreed

[USE eero AT chromium.org, 2015/07/14 23:44:13]

Done.

 };
 
 struct SameSizeAsWebMouseWheelEvent : public SameSizeAsWebMouseEvent {