Better diagnosing leaked activities.

Test: manual
Bug: 181356264
Change-Id: I9bf843a1d26bc4cf255c1b8d2cce0febeaa4c4fe
diff --git a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
index b3c1240..0edfbed 100644
--- a/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
+++ b/tests/src/com/android/launcher3/ui/AbstractLauncherUiTest.java
@@ -151,23 +151,30 @@
     }
 
     public static String dumpHprofData() {
-        if (sDumpWasGenerated) return "dump has already been generated by another test";
-        try {
-            final String fileName = getInstrumentation().getTargetContext().getFilesDir().getPath()
-                    + "/ActivityLeakHeapDump.hprof";
-            if (TestHelpers.isInLauncherProcess()) {
-                Debug.dumpHprofData(fileName);
-            } else {
-                final UiDevice device = UiDevice.getInstance(getInstrumentation());
-                device.executeShellCommand(
-                        "am dumpheap " + device.getLauncherPackageName() + " " + fileName);
+        String result;
+        if (sDumpWasGenerated) {
+            result = "dump has already been generated by another test";
+        } else {
+            try {
+                final String fileName =
+                        getInstrumentation().getTargetContext().getFilesDir().getPath()
+                                + "/ActivityLeakHeapDump.hprof";
+                if (TestHelpers.isInLauncherProcess()) {
+                    Debug.dumpHprofData(fileName);
+                } else {
+                    final UiDevice device = UiDevice.getInstance(getInstrumentation());
+                    device.executeShellCommand(
+                            "am dumpheap " + device.getLauncherPackageName() + " " + fileName);
+                }
+                sDumpWasGenerated = true;
+                result = "memory dump filename: " + fileName;
+            } catch (Throwable e) {
+                Log.e(TAG, "dumpHprofData failed", e);
+                result = "failed to save memory dump";
             }
-            sDumpWasGenerated = true;
-            return "memory dump filename: " + fileName;
-        } catch (Throwable e) {
-            Log.e(TAG, "dumpHprofData failed", e);
-            return "failed to save memory dump";
         }
+        return result
+                + ". Full list of activities: " + ACTIVITY_LEAK_TRACKER.getActivitiesList();
     }
 
     protected AbstractLauncherUiTest() {
diff --git a/tests/src/com/android/launcher3/ui/ActivityLeakTracker.java b/tests/src/com/android/launcher3/ui/ActivityLeakTracker.java
index dd216c7..2db7472 100644
--- a/tests/src/com/android/launcher3/ui/ActivityLeakTracker.java
+++ b/tests/src/com/android/launcher3/ui/ActivityLeakTracker.java
@@ -25,6 +25,7 @@
 import com.android.launcher3.tapl.TestHelpers;
 
 import java.util.WeakHashMap;
+import java.util.stream.Collectors;
 
 public class ActivityLeakTracker implements Application.ActivityLifecycleCallbacks {
     private final WeakHashMap<Activity, Boolean> mActivities = new WeakHashMap<>();
@@ -81,4 +82,9 @@
 
         return mActivities.size() <= 2;
     }
+
+    public String getActivitiesList() {
+        return mActivities.keySet().stream().map(a -> a.getClass().getSimpleName())
+                .collect(Collectors.joining(","));
+    }
 }