aaudio: minor cleanup in clock model

Init mMaxMeasuredLatenessNanos
Use default destructor.

Bug: 137009840
Test: atest CtsNativeMediaAAudioTestCases
Change-Id: Ia9b42e4754047f5e87205c4adbc3329a1b96e74b
diff --git a/media/libaaudio/src/client/IsochronousClockModel.cpp b/media/libaaudio/src/client/IsochronousClockModel.cpp
index bd46d05..f0dcd44 100644
--- a/media/libaaudio/src/client/IsochronousClockModel.cpp
+++ b/media/libaaudio/src/client/IsochronousClockModel.cpp
@@ -47,6 +47,7 @@
         , mMarkerNanoTime(0)
         , mSampleRate(48000)
         , mFramesPerBurst(48)
+        , mBurstPeriodNanos(0) // this will be updated before use
         , mMaxMeasuredLatenessNanos(0)
         , mLatenessForDriftNanos(kInitialLatenessForDriftNanos)
         , mState(STATE_STOPPED)
@@ -57,9 +58,6 @@
     }
 }
 
-IsochronousClockModel::~IsochronousClockModel() {
-}
-
 void IsochronousClockModel::setPositionAndTime(int64_t framePosition, int64_t nanoTime) {
     ALOGV("setPositionAndTime, %lld, %lld", (long long) framePosition, (long long) nanoTime);
     mMarkerFramePosition = framePosition;
@@ -186,7 +184,7 @@
             // Calculate upper region that will trigger a drift forwards.
             mLatenessForDriftNanos = mMaxMeasuredLatenessNanos - (mMaxMeasuredLatenessNanos >> 4);
         } else { // decrease
-            // If these is an outlier in lateness then mMaxMeasuredLatenessNanos can go high
+            // If this is an outlier in lateness then mMaxMeasuredLatenessNanos can go high
             // and stay there. So we slowly reduce mMaxMeasuredLatenessNanos for better
             // long term stability. The two opposing forces will keep mMaxMeasuredLatenessNanos
             // within a reasonable range.