Add a way to read the last AutofillSelection.

- Check UID to make sure one service cannot read FillSelections of other
  services
- Add id to Dataset to allow to tag the datasets. This id is then found
  in the FillSelection.Event
- Add clientState to FillSelection to allow service to store more data

Fixes: 36871500
Test: CtsAutoFillServiceTestCases
Change-Id: Ice894245508227265294a1c59ea97842175e5aec
diff --git a/core/java/android/service/autofill/AutofillService.java b/core/java/android/service/autofill/AutofillService.java
index 5e49b8f..8fcb87c 100644
--- a/core/java/android/service/autofill/AutofillService.java
+++ b/core/java/android/service/autofill/AutofillService.java
@@ -285,4 +285,22 @@
         // TODO(b/33197203): Remove when GCore has migrated off this API
         getSystemService(AutofillManager.class).disableOwnedAutofillServices();
     }
+
+    /**
+     * Returns the {@link FillEventHistory.Event events} since the last {@link FillResponse} was
+     * returned.
+     *
+     * <p>The history is not persisted over reboots.
+     *
+     * @return The history or {@code null} if there are not events.
+     */
+    @Nullable public final FillEventHistory getFillEventHistory() {
+        AutofillManager afm = getSystemService(AutofillManager.class);
+
+        if (afm == null) {
+            return null;
+        } else {
+            return afm.getFillEventHistory();
+        }
+    }
 }