GN: Remove unneeded version header visibility rule.

These Chrome targets are now migrated to use the encapsulated API.

Bug: angleproject:2551
Change-Id: I6970f7ad85af089fd41c79476a2bdd4e605949c3
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3248143
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

BUILD.gn

@@ -713,14 +713,6 @@ angle_source_set("angle_version") {
       ":libGLESv2_capture_complement",
     ]
   }
-
-  # TODO(jmadill): Remove once headers isolated. http://anglebug.com/2551
-  if (build_with_chromium) {
-    visibility += [
-      "//content/browser:browser",
-      "//gpu/command_buffer/service:gles2_sources",
-    ]
-  }
 }
 
 angle_source_set("angle_version_info") {