Replace dict.has_key(x) with x in dict for performance gain

svn: r10874

src/PluginUtils/_PluginWindows.py

@@ -400,7 +400,7 @@ class ToolManagedWindowBase(ManagedWindow.ManagedWindow):
         before the report executes. This task should only be called in
         the add_user_options task."""
         
-        if self.frames.has_key(frame_name):
+        if frame_name in self.frames:
             self.frames[frame_name].append((label_text, widget))
         else:
             self.frames[frame_name] = [(label_text, widget)]