Fix a menu crash.
Fix a menu crash.

The menu's host window, the message window that receives notifications from the native menu about selection changes, is destroyed, however if the menu is still active it will continue to send messages to it. SDK docs say properties set with SetProp should be removed with RemoveProp before a window is finally NCDESTROYed. The code wasn't doing this, so it was still theoretically possible for the code in the message window's window procedure to locate "something" on that property.

http://crbug.com/14594
TEST=none

Review URL: http://codereview.chromium.org/147230

git-svn-id: http://src.chromium.org/svn/trunk/src@19411 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 79534840f117e70494bea174f90fe7b2871a02d5
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser