Eraser tool type plumbing from ui/events to web events and PPAPI.

ppapi/c/ppb_input_event.h

Index: ppapi/c/ppb_input_event.h
diff --git a/ppapi/c/ppb_input_event.h b/ppapi/c/ppb_input_event.h
index ca2bf152b9ddb65a662c2e5948cdbdf9c742d538..edf9c02ebc9c497235a6b9ec072fe943e09e4079 100644
--- a/ppapi/c/ppb_input_event.h
+++ b/ppapi/c/ppb_input_event.h
@@ -214,7 +214,9 @@ typedef enum {
   PP_INPUTEVENT_MODIFIER_CAPSLOCKKEY = 1 << 9,
   PP_INPUTEVENT_MODIFIER_NUMLOCKKEY = 1 << 10,
   PP_INPUTEVENT_MODIFIER_ISLEFT = 1 << 11,
-  PP_INPUTEVENT_MODIFIER_ISRIGHT = 1 << 12
+  PP_INPUTEVENT_MODIFIER_ISRIGHT = 1 << 12,
+  // PPAPI does not use modifiers 13 through 18.
+  PP_INPUTEVENT_MODIFIER_ISERASER = 1 << 19,

[bbudge, 2016/08/30 20:46:37]

Just define this as bit 13, since this isn't a modifier in the Webkit world.

Pepper was designed before pointer events, so we need to mark mouse events with
that extra information using modifiers. Given that, and as long as you're here,
why not define PP_INPUTEVENT_MODIFIER_ISPEN as well?

[denniskempin, 2016/08/30 21:09:41]

Done. Added ISPEN as well. 

 } PP_InputEvent_Modifier;
 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_InputEvent_Modifier, 4);
 
@@ -227,7 +229,8 @@ typedef enum {
   PP_INPUTEVENT_MOUSEBUTTON_NONE = -1,
   PP_INPUTEVENT_MOUSEBUTTON_LEFT = 0,
   PP_INPUTEVENT_MOUSEBUTTON_MIDDLE = 1,
-  PP_INPUTEVENT_MOUSEBUTTON_RIGHT = 2
+  PP_INPUTEVENT_MOUSEBUTTON_RIGHT = 2,
+  PP_INPUTEVENT_MOUSEBUTTON_ERASER = 3

[bradnelson, 2016/08/30 18:19:29]

Leftover, I thought the idea was you'd use the modifier?

[denniskempin, 2016/08/30 20:49:35]

Done.

 } PP_InputEvent_MouseButton;
 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_InputEvent_MouseButton, 4);