Add IPCs to allow assistive technology to scroll the page

content/renderer/renderer_accessibility.h

Index: content/renderer/renderer_accessibility.h
===================================================================
--- content/renderer/renderer_accessibility.h	(revision 112764)
+++ content/renderer/renderer_accessibility.h	(working copy)
@@ -82,9 +82,12 @@
   // Handlers for messages from the browser to the renderer.
   void OnAccessibilityDoDefaultAction(int acc_obj_id);
   void OnAccessibilityNotificationsAck();
+  void OnChangeScrollPosition(int acc_obj_id, int scroll_x, int scroll_y);
   void OnEnableAccessibility();
   void OnSetAccessibilityFocus(int acc_obj_id);
 
+  void OnSetTextSelection(int acc_obj_id, int start_offset, int end_offset);
+
   // Whether or not this notification typically needs to send
   // updates to its children, too.
   bool ShouldIncludeChildren(const Notification& notification);