Session: Add a shortcut in detecting if a window that contains the wallpaper is null or not

originally, a null window would be detected in WindowManagerService, an exception would be thrown, and then that would be caught in Session

Change-Id: Ib937d029bb7a27dac15ff38ecf3b4fbb51bc417c
Base: more fix Active Display

fix http://jira.omnirom.org/browse/OMNI-352
fix http://jira.omnirom.org/browse/OMNI-357

Change-Id: Ibdd9617ce472213520261358bb6b77e9ff5eb523
Cursor leakage due to cancellation signal

If a query call was cancelled, the cursor adaptor might leak. The
adaptor is now closed if any exception is thrown during query.

Change-Id: Ic4c2edeaf2fcef56b4ef59484a36d3233aa12dbc
Revert "Fix fatal exception due to missing looper for current thread."

This reverts commit 54de8acf306d5ae410690e54d675ca376e743480.

Change-Id: If17bdc140ec07605f240d89e53a788050f28ee3a
Fix a JNI local reference leak in MediaDrm

A reference leak was found in the subtitle usecase that also
applies to android_media_MediaDrm.cpp
(Code taken from the similar fix in android_media_MediaPlayer.cpp)

Change-Id: Icc4b25e4adc9a600ff4ac99a7a8478bb55a6e348