Merge changes I1811ad12,I8d8800a6

* changes:
  Bug fix: Do not track the looper exception if the session is not sampled
  Bug fix: looper not enabled

core/java/com/android/internal/os/LooperStats.java

@@ -126,9 +126,11 @@ public class LooperStats implements Looper.Observer {
         }
 
         DispatchSession session = (DispatchSession) token;
-        Entry entry = findEntry(msg, /* allowCreateNew= */true);
-        synchronized (entry) {
-            entry.exceptionCount++;
+        Entry entry = findEntry(msg, /* allowCreateNew= */session != DispatchSession.NOT_SAMPLED);
+        if (entry != null) {
+            synchronized (entry) {
+                entry.exceptionCount++;
+            }
         }
 
         recycleSession(session);

core/tests/coretests/src/com/android/internal/os/LooperStatsTest.java

@@ -137,6 +137,26 @@ public final class LooperStatsTest {
         assertThat(entry.maxCpuUsageMicros).isEqualTo(0);
     }
 
+    @Test
+    public void testThrewException_notSampled() {
+        TestableLooperStats looperStats = new TestableLooperStats(2, 100);
+
+        Object token = looperStats.messageDispatchStarting();
+        looperStats.tickRealtime(10);
+        looperStats.tickThreadTime(10);
+        looperStats.messageDispatched(token, mHandlerFirst.obtainMessage(0));
+        assertThat(looperStats.getEntries()).hasSize(1);
+
+        // Will not be sampled so does not contribute to any entries.
+        Object token2 = looperStats.messageDispatchStarting();
+        looperStats.tickRealtime(100);
+        looperStats.tickThreadTime(10);
+        looperStats.dispatchingThrewException(
+                token2, mHandlerSecond.obtainMessage(7), new ArithmeticException());
+        assertThat(looperStats.getEntries()).hasSize(1);
+        assertThat(looperStats.getEntries().get(0).messageCount).isEqualTo(1);
+    }
+
     @Test
     public void testMultipleMessagesDispatched() {
         TestableLooperStats looperStats = new TestableLooperStats(2, 100);

services/core/java/com/android/server/LooperStatsService.java

@@ -59,7 +59,8 @@ public class LooperStatsService extends Binder {
 
     private final Context mContext;
     private final LooperStats mStats;
-    private boolean mEnabled = DEFAULT_ENABLED;
+    // Default should be false so that the first call to #setEnabled installed the looper observer.
+    private boolean mEnabled = false;
 
     private LooperStatsService(Context context, LooperStats stats) {
         this.mContext = context;