Wires up drags to pointer watcher adapter.

ui/views/pointer_watcher.h

Index: ui/views/pointer_watcher.h
diff --git a/ui/views/pointer_watcher.h b/ui/views/pointer_watcher.h
index 8270683214e99f946e0629d433a31662fb71d3a0..725d4929875fce8ff663bfdccee5885dc3d0b607 100644
--- a/ui/views/pointer_watcher.h
+++ b/ui/views/pointer_watcher.h
@@ -19,6 +19,17 @@ class PointerEvent;
 namespace views {
 class Widget;
 
+// When pointer watchers are added they need to specify which events they want
+// to receive. BASIC means they receive only presses, releases, capture and
+// wheel events, MOVES means they receive move events in addition, and DRAGS
+// means
+// they receive move and drag events in addition.
+enum class PointerWatcherEventTypes {
+  BASIC = 0x01,

[sky, 2016/08/26 19:58:57]

This isn't used as a bitmask, right? In other words you shouldn't need explicit
values, right?

[sammiequon, 2016/08/26 21:48:04]

Right I thought I'd be using one but forgot to change it. Done.

+  MOVES = 0x02,
+  DRAGS = 0x04
+};
+
 // An interface for read-only observation of pointer events (in particular, the
 // events cannot be marked as handled). Only certain event types are supported.
 // The |target| is the top-level widget that will receive the event, if any.