DO NOT MERGE ANYWHERE (nyc-dr1-dev) audioflinger: add watchdog on main mutex

Check every 10 seconds if main audioflinger mutex can be acquired and
trigger audioserver process restart if not.
This will allow to capture tombstones of locked up situations and avoid
the disruption of a system_server restart.

Bug: 30737845
Bug: 30388410
Change-Id: I8a78b8cf813982f70ea598a6d42affc0ecaa76c9
(cherry picked from commit 17a58b2560c38a8e31a38186f9ab6eb98a38e229)
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index c56dcc1..e334d80 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -58,6 +58,7 @@
 #include "SpdifStreamOut.h"
 #include "AudioHwDevice.h"
 #include "LinearMap.h"
+#include "LockWatch.h"
 
 #include <powermanager/IPowerManager.h>
 
@@ -630,6 +631,7 @@
     };
 
     mutable     Mutex                               mLock;
+                sp<LockWatch>                       mLockWatch;
                 // protects mClients and mNotificationClients.
                 // must be locked after mLock and ThreadBase::mLock if both must be locked
                 // avoids acquiring AudioFlinger::mLock from inside thread loop.