ash: Refactor touch hud drawing to ash/touch_hud as a separate component.

ash/BUILD.gn

Index: ash/BUILD.gn
diff --git a/ash/BUILD.gn b/ash/BUILD.gn
index 3a885acd874dc0a6a712bbbf58dc725e91940b05..476ee86f3ada0e4d042b71fcfc1902ae1a21d42e 100644
--- a/ash/BUILD.gn
+++ b/ash/BUILD.gn
@@ -26,6 +26,7 @@ component("ash") {
     "//ash/strings",
   ]
   deps = [
+    "//ash/touch_hud",
     "//base",
     "//base:i18n",
     "//base/third_party/dynamic_annotations",
@@ -349,6 +350,7 @@ test("ash_unittests") {
     ":test_support_with_content",
     "//ash/resources",
     "//ash/strings",
+    "//ash/touch_hud",
     "//base",
     "//base/test:test_support",
     "//components/signin/core/account_id",