Add "File->Save snapshot" menu item to export the displayed screen.

scripts/newbitmaps/lib/bmpblock.py

 #!/usr/bin/python -tt
 # Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """A BmpBlock class"""
 
 import os
 import types
 import yaml
@@ skipping 84 matching lines @@
     self.displayer = displayer
 
 
   def Redisplay(self):
     """Redisplay contents."""
     if self.displayer:
       if self.current_screen:
         sc = self.yaml['screens'][self.current_screen]
         slist = [(x,y,self.yaml['images'][z]) for x,y,z in sc]
         self.displayer.DisplayScreen(self.current_screen, slist)
+
+  def Saveit(self):
+    """Save current screen to file."""
+    if self.displayer:
+      if self.current_screen:
+        sc = self.yaml['screens'][self.current_screen]
+        slist = [(x,y,self.yaml['images'][z]) for x,y,z in sc]
+        self.displayer.SaveScreen(self.current_screen, slist)