am 51cce58c: Ensure the plugin\'s native code is never called with an invalid NPP pointer.

Merge commit '51cce58c45591fdf3d0cd59a92aeb18182eaeded' into eclair-mr2-plus-aosp

* commit '51cce58c45591fdf3d0cd59a92aeb18182eaeded':
  Ensure the plugin's native code is never called with an invalid NPP pointer.