Revert "Sensor: Add RotationVectorSensor2"

The implementation does not work as-is and the latest version of
Google Maps no longer needs it.

This reverts commit 45c5aa0ce71904ad8b00d5eba0627770b35b03ab.

Change-Id: I89b3730e93eb774dc2b9dace645d08cbfb311647
GlES2: Add NULL check

Check for NULL before calling thread specific glGetString.

CRs-fixed: 569609

Change-Id: Ifee8257152ba7ca7a05df5d7b113171b71d16c82
surfaceflinger: Set max acquired buffer count

If triple framebuffers are enabled, the number of acquired
buffers isn't increased by default. Set the count to one less
than the max buffers to make sure all three buffers come into
play.

Change-Id: I65054ed4004607f5be68c893f6f621e821cfbf1c
Merge "Revert "Sensor: Add RotationVectorSensor2"" into cm-11.0