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/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index 0f82f91e..b26563cd2 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -390,6 +390,12 @@
   // both renderer accessibility, and a native browser accessibility tree.
   virtual bool IsFullAccessibilityModeForTesting() const = 0;
 
+  virtual ui::AXMode GetAccessibilityMode() const = 0;
+
+  virtual void SetAccessibilityMode(ui::AXMode mode) = 0;
+
+  virtual base::string16 DumpAccessibilityTree(bool internal) = 0;
+
   virtual const PageImportanceSignals& GetPageImportanceSignals() const = 0;
 
   // Tab navigation state ------------------------------------------------------