gpu_display: amend GpuDisplay to import and attach EventDevices

This change also includes stubs for the wayland and x11 impls.

TEST=compiles
BUG=chromium:1023975

Change-Id: Ia2bcb5c2ed75ea47071dd77e149e60901a56595c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1930407
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Noah Gold <nkgold@google.com>
Tested-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>

gpu_display/src/gpu_display_wl.rs

@@ -12,7 +12,7 @@ mod dwl;
 
 use dwl::*;
 
-use crate::{DisplayT, GpuDisplayError, GpuDisplayFramebuffer};
+use crate::{DisplayT, EventDevice, GpuDisplayError, GpuDisplayFramebuffer};
 
 use std::cell::Cell;
 use std::collections::HashMap;
@@ -341,6 +341,16 @@ impl DisplayT for DisplayWl {
             None => debug_assert!(false, "invalid surface_id {}", surface_id),
         }
     }
+
+    fn import_event_device(&mut self, _event_device: EventDevice) -> Result<u32, GpuDisplayError> {
+        Err(GpuDisplayError::Unsupported)
+    }
+    fn release_event_device(&mut self, _event_device_id: u32) {
+        // unsupported
+    }
+    fn attach_event_device(&mut self, surface_id: u32, event_device_id: u32) {
+        // unsupported
+    }
 }
 
 impl AsRawFd for DisplayWl {

gpu_display/src/gpu_display_x.rs

@@ -22,7 +22,7 @@ use std::rc::Rc;
 
 use libc::{shmat, shmctl, shmdt, shmget, IPC_CREAT, IPC_PRIVATE, IPC_RMID};
 
-use crate::{DisplayT, GpuDisplayError, GpuDisplayFramebuffer};
+use crate::{DisplayT, EventDevice, GpuDisplayError, GpuDisplayFramebuffer};
 
 use data_model::VolatileSlice;
 
@@ -638,6 +638,15 @@ impl DisplayT for DisplayX {
     fn set_position(&mut self, surface_id: u32, x: u32, y: u32) {
         // unsupported
     }
+    fn import_event_device(&mut self, _event_device: EventDevice) -> Result<u32, GpuDisplayError> {
+        Err(GpuDisplayError::Unsupported)
+    }
+    fn release_event_device(&mut self, _event_device_id: u32) {
+        // unsupported
+    }
+    fn attach_event_device(&mut self, surface_id: u32, event_device_id: u32) {
+        // unsupported
+    }
 }
 
 impl AsRawFd for DisplayX {

gpu_display/src/lib.rs

@@ -155,6 +155,9 @@ trait DisplayT: AsRawFd {
     fn flip_to(&mut self, surface_id: u32, import_id: u32);
     fn close_requested(&self, surface_id: u32) -> bool;
     fn set_position(&mut self, surface_id: u32, x: u32, y: u32);
+    fn import_event_device(&mut self, event_device: EventDevice) -> Result<u32, GpuDisplayError>;
+    fn release_event_device(&mut self, event_device_id: u32);
+    fn attach_event_device(&mut self, surface_id: u32, event_device_id: u32);
 }
 
 /// A connection to the compositor and associated collection of state.
@@ -291,6 +294,21 @@ impl GpuDisplay {
     pub fn set_position(&mut self, surface_id: u32, x: u32, y: u32) {
         self.inner.set_position(surface_id, x, y)
     }
+
+    pub fn import_event_device(
+        &mut self,
+        event_device: EventDevice,
+    ) -> Result<u32, GpuDisplayError> {
+        self.inner.import_event_device(event_device)
+    }
+
+    pub fn release_event_device(&mut self, event_device_id: u32) {
+        self.inner.release_event_device(event_device_id)
+    }
+
+    pub fn attach_event_device(&mut self, surface_id: u32, event_device_id: u32) {
+        self.inner.attach_event_device(surface_id, event_device_id);
+    }
 }
 
 impl AsRawFd for GpuDisplay {