Remove background color for dino touch controller

Bug: 1156791
Change-Id: I563fd1965ab9f2fb57cd011522c2d9e3e44f2da9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2584030Reviewed-by: Edward Jung (EMEA) <edwardjung@chromium.org>
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Cr-Commit-Position: refs/heads/master@{#835707}

components/neterror/resources/neterror.css

@@ -851,7 +851,6 @@ whereas Blink does not. */
 }
 
 .offline .controller {
-  background: rgba(247,247,247, .1);
   height: 100vh;
   left: 0;
   position: absolute;