Add percentiles

Change-Id: Ieb6badd177bb6f67dda199dfcb3e0f483c8c4e59
diff --git a/libs/hwui/JankTracker.h b/libs/hwui/JankTracker.h
index aa554cd..3d4929b 100644
--- a/libs/hwui/JankTracker.h
+++ b/libs/hwui/JankTracker.h
@@ -54,8 +54,11 @@
     void reset();
 
 private:
+    uint32_t findPercentile(int p);
+
     JankBucket mBuckets[NUM_BUCKETS];
     int64_t mThresholds[NUM_BUCKETS];
+    uint32_t mFrameCounts[128];
 
     int64_t mFrameInterval;
     uint32_t mTotalFrameCount;