Move AccessibilityUI from content/ to chrome/

Move the code for chrome://accessibility out of content/.

Bug: 865733
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: I4169a666cbf73f5ea9c3383d7aca44577b24193b
Reviewed-on: https://chromium-review.googlesource.com/1144187
Commit-Queue: James Wallace-Lee <[email protected]>
Reviewed-by: John Abd-El-Malek <[email protected]>
Reviewed-by: Dominic Mazzoni <[email protected]>
Cr-Commit-Position: refs/heads/master@{#577273}
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 2c01bbb9..a824921 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -82,6 +82,8 @@
     "about_flags.h",
     "accessibility/accessibility_permission_context.cc",
     "accessibility/accessibility_permission_context.h",
+    "accessibility/accessibility_ui.cc",
+    "accessibility/accessibility_ui.h",
     "after_startup_task_utils.cc",
     "after_startup_task_utils.h",
     "app_controller_mac.h",