Rename "test" ozone platform to "headless"

ui/ozone/BUILD.gn

Index: ui/ozone/BUILD.gn
diff --git a/ui/ozone/BUILD.gn b/ui/ozone/BUILD.gn
index fb13cd3ef4b01fa726c7b4e2f23bb80a3d159e9f..f52969253c46c2b01aa519142e237c40eed12a64 100644
--- a/ui/ozone/BUILD.gn
+++ b/ui/ozone/BUILD.gn
@@ -19,9 +19,9 @@ if (ozone_platform_egltest) {
   ozone_platform_deps += [ "platform/egltest" ]
 }
 
-if (ozone_platform_test) {
-  ozone_platforms += [ "test" ]
-  ozone_platform_deps += [ "platform/test" ]
+if (ozone_platform_headless) {
+  ozone_platforms += [ "headless" ]
+  ozone_platform_deps += [ "platform/headless" ]
 }
 
 if (ozone_platform_caca) {
@@ -131,6 +131,7 @@ component("ozone") {
         "//ui/display/types",
         "//ui/display/util",
         "//ui/events",
+        "//ui/events/devices",
         "//ui/events/ozone:events_ozone",
         "//ui/gfx",
         "//ui/gfx/geometry",