Add setSelection function to automation API.

chrome/browser/extensions/api/automation_internal/automation_action_adapter.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_AUTOMATION_INTERNAL_AUTOMATION_ACTION_ADAPTER_H_
 #define CHROME_BROWSER_EXTENSIONS_API_AUTOMATION_INTERNAL_AUTOMATION_ACTION_ADAPTER_H_
 
 #include "ui/gfx/geometry/point.h"
 
 namespace extensions {
 
 // Adapts an object to receive actions from the Automation extension API.
 class AutomationActionAdapter {
  public:
   // Performs a default action (e.g. click, check) on the target node.
   virtual void DoDefault(int32 id) = 0;
 
   // Performs a focus action on the target node.
   virtual void Focus(int32 id) = 0;
 
   // Makes the node visible by scrolling; does not change nodes from hidden to
   // shown.
   virtual void MakeVisible(int32 id) = 0;
 
-  // Sets selection for a start and end index (usually only relevant on text
-  // fields).
-  virtual void SetSelection(int32 id, int32 start, int32 end) = 0;
+  // Sets selection for anchor and focus node/offset pairs.  Also used to set
+  // selection in text fields.
+  virtual void SetSelection(int32 anchor_id,
+                            int32 anchor_offset,
+                            int32 focus_id,
+                            int32 focus_offset) = 0;
 
   // Shows the context menu resulting from a right click.
   virtual void ShowContextMenu(int32 id) = 0;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_AUTOMATION_INTERNAL_AUTOMATION_ACTION_ADAPTER_H_