Reland: Implement Aura side of unified touch text selection for contents

ui/touch_selection/touch_handle.h

Index: ui/touch_selection/touch_handle.h
diff --git a/ui/touch_selection/touch_handle.h b/ui/touch_selection/touch_handle.h
index f6863a23ca076c49f2db2be10c916244ccc5c722..eaca7caa92e05a6eb583bba368006c2dde40da88 100644
--- a/ui/touch_selection/touch_handle.h
+++ b/ui/touch_selection/touch_handle.h
@@ -95,12 +95,16 @@ class UI_TOUCH_SELECTION_EXPORT TouchHandle {
   TouchHandleOrientation orientation() const { return orientation_; }
 
  private:
+  friend class TouchSelectionControllerAuraTest;

[jdduke (slow), 2015/01/28 16:35:32]

Hmm, this friend declaration is a shame, I guess the alternative is having the
client return a drawable with some shared state?

[mohsen, 2015/02/22 23:23:09]

Fixed, please take another look.

+
   void BeginDrag();
   void EndDrag();
   void BeginFade();
   void EndFade();
   void SetAlpha(float alpha);
 
+  TouchHandleDrawable* drawable_for_testing() const { return drawable_.get(); }
+
   scoped_ptr<TouchHandleDrawable> drawable_;
 
   TouchHandleClient* const client_;