Added autofill options on Developer Options screen.

Test: manual verification
Test: atest AutofillResetOptionsPreferenceControllerTest\
            AutofillLoggingLevelPreferenceControllerTest
Test: runtest --path packages/apps/Settings/tests/unit/src/com/android/settings/core/PreferenceControllerContractTest.java
Fixes: 65700540

Change-Id: I6b35fbf549529f4d97df164ce3fb6d641ee37650

src/com/android/settings/development/autofill/AutofillDeveloperSettingsObserver.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.development.autofill;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.database.ContentObserver;
+import android.net.Uri;
+import android.os.Handler;
+import android.os.UserHandle;
+import android.provider.Settings;
+
+final class AutofillDeveloperSettingsObserver extends ContentObserver {
+
+    private final Runnable mChangeCallback;
+    private final ContentResolver mResolver;
+
+    public AutofillDeveloperSettingsObserver(Context context, Runnable changeCallback) {
+        super(new Handler());
+
+        mResolver = context.getContentResolver();
+        mChangeCallback = changeCallback;
+    }
+
+    public void register() {
+        mResolver.registerContentObserver(Settings.Global.getUriFor(
+                Settings.Global.AUTOFILL_LOGGING_LEVEL), false, this,
+                UserHandle.USER_ALL);
+        mResolver.registerContentObserver(Settings.Global.getUriFor(
+                Settings.Global.AUTOFILL_MAX_PARTITIONS_SIZE), false, this,
+                UserHandle.USER_ALL);
+        mResolver.registerContentObserver(Settings.Global.getUriFor(
+                Settings.Global.AUTOFILL_MAX_VISIBLE_DATASETS), false, this,
+                UserHandle.USER_ALL);
+    }
+
+    public void unregister() {
+        mResolver.unregisterContentObserver(this);
+    }
+
+    @Override
+    public void onChange(boolean selfChange, Uri uri, int userId) {
+        mChangeCallback.run(); // Run Forrest, Run!
+    }
+}