Remove X11 deps from accessibility

This fixes pure ozone/wayland build on systems where
X11 is not available

Change-Id: Ib4e41c2fd149b48586623183d8fa656591415361
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2228649Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Maksim Sisov <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#775056}

content/browser/BUILD.gn

@@ -2338,8 +2338,6 @@ jumbo_source_set("browser") {
       "//build/config/linux/atspi2",
     ]
 
-    deps += [ "//ui/gfx/x" ]
-
     if (use_glib) {
       configs += [ "//build/config/linux:glib" ]
     }