AppErrors: Refine notion of "interesting" processes for b/g ANRs.

- SystemUI is always interesting, regardless of whether it's currently
  displaying any interesting activities or not.
- Any process that hasOverlayUI or hasTopUI is considered interesting.
- Any process that hosts an active foreground service is considered
  interesting.

Bug: 36383925
Test: manual
Change-Id: I852a00344f913200020c4f80500e38ff101fe05d
diff --git a/services/core/java/com/android/server/am/AppErrors.java b/services/core/java/com/android/server/am/AppErrors.java
index ba72dcf..d6bfb35 100644
--- a/services/core/java/com/android/server/am/AppErrors.java
+++ b/services/core/java/com/android/server/am/AppErrors.java
@@ -751,6 +751,26 @@
         mAppsNotReportingCrashes.add(proc.info.packageName);
     }
 
+    static boolean isInterestingForBackgroundTraces(ProcessRecord app) {
+        // The system_server is always considered interesting.
+        if (app.pid == MY_PID) {
+            return true;
+        }
+
+        // A package is considered interesting if any of the following is true :
+        //
+        // - It's displaying an activity.
+        // - It's the SystemUI.
+        // - It has an overlay or a top UI visible.
+        //
+        // NOTE: The check whether a given ProcessRecord belongs to the systemui
+        // process is a bit of a kludge, but the same pattern seems repeated at
+        // several places in the system server.
+        return app.isInterestingToUserLocked() ||
+            (app.info != null && "com.android.systemui".equals(app.info.packageName)) ||
+            (app.hasTopUi || app.hasOverlayUi);
+    }
+
     final void appNotResponding(ProcessRecord app, ActivityRecord activity,
             ActivityRecord parent, boolean aboveSystem, final String annotation) {
         ArrayList<Integer> firstPids = new ArrayList<Integer>(5);
@@ -812,7 +832,7 @@
             firstPids.add(app.pid);
 
             // Don't dump other PIDs if it's a background ANR
-            isSilentANR = !showBackground && !app.isInterestingToUserLocked() && app.pid != MY_PID;
+            isSilentANR = !showBackground && !isInterestingForBackgroundTraces(app);
             if (!isSilentANR) {
                 int parentPid = app.pid;
                 if (parent != null && parent.app != null && parent.app.pid > 0) {
diff --git a/services/core/java/com/android/server/am/ProcessRecord.java b/services/core/java/com/android/server/am/ProcessRecord.java
index 3c5c5fd..b025385 100644
--- a/services/core/java/com/android/server/am/ProcessRecord.java
+++ b/services/core/java/com/android/server/am/ProcessRecord.java
@@ -520,6 +520,14 @@
                 return true;
             }
         }
+
+        final int servicesSize = services.size();
+        for (int i = 0; i < servicesSize; i++) {
+            ServiceRecord r = services.valueAt(i);
+            if (r.isForeground) {
+                return true;
+            }
+        }
         return false;
     }