Overhaul Mandoline event transport code

ui/mojo/events/input_event_constants.mojom

Index: ui/mojo/events/input_event_constants.mojom
diff --git a/ui/mojo/events/input_event_constants.mojom b/ui/mojo/events/input_event_constants.mojom
index b3e0ea1f663ef3f2009d200bf22859aa8ada5688..a3e65e5feed462c3c525850a42fbeb51010186d1 100644
--- a/ui/mojo/events/input_event_constants.mojom
+++ b/ui/mojo/events/input_event_constants.mojom
@@ -12,6 +12,7 @@ enum EventType {
   POINTER_DOWN,
   POINTER_MOVE,
   POINTER_UP,
+  WHEEL,
 };
 
 // This mirrors ui::EventFlags
@@ -41,6 +42,15 @@ enum MouseEventFlags {
 };
 
 enum PointerKind {
-  TOUCH,
+  UNKNOWN,

[sky, 2015/09/14 19:27:25]

When would the pointer kind be unknown? You should document this here as others
are bound to ask too.

[rjkroege, 2015/09/14 21:07:38]

I can't think of a good reason why we need this. Removed.

   MOUSE,
+  PEN,
+  TOUCH,
+};
+
+enum WheelMode {
+  PIXEL,
+  LINE,
+  PAGE,
+  SCALING,
 };