Allow taking screen shot of a non child window which has delegate to paint.

ash/test/test_screenshot_delegate.h

 // Copyright 2013 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 ASH_TEST_TEST_SCREENSHOT_DELEGATE_H_
 #define ASH_TEST_TEST_SCREENSHOT_DELEGATE_H_
 
 #include "ash/screenshot_delegate.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
@@ skipping 15 matching lines @@
   bool CanTakeScreenshot() override;
 
   int handle_take_screenshot_count() const {
     return handle_take_screenshot_count_;
   }
 
   int handle_take_partial_screenshot_count() const {
     return handle_take_partial_screenshot_count_;
   }
 
-  int handle_take_window_screenshot_count() const {
-    return handle_take_window_screenshot_count_;
-  }
-
   const gfx::Rect& last_rect() const { return last_rect_; }
 
+  const aura::Window* GetSelectedWindowAndReset();
+
   void set_can_take_screenshot(bool can_take_screenshot) {
     can_take_screenshot_ = can_take_screenshot;
   }
 
  private:
   int handle_take_screenshot_count_;
   int handle_take_partial_screenshot_count_;
-  int handle_take_window_screenshot_count_;
   gfx::Rect last_rect_;
   bool can_take_screenshot_;
+  aura::Window* selected_window_;
 
   DISALLOW_COPY_AND_ASSIGN(TestScreenshotDelegate);
 };
 
 }  // namespace test
 }  // namespace ash
 
 #endif  // ASH_TEST_TEST_SCREENSHOT_DELEGATE_H_