AutofillPreferences: Modify UI only when it's available.

chrome/android/java/src/org/chromium/chrome/browser/preferences/autofill/AutofillPreferences.java

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/autofill/AutofillPreferences.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/autofill/AutofillPreferences.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/autofill/AutofillPreferences.java
index 0602f73cedb3d1887e436d8d7b5067657617d360..b1efafe6f12c188f4d060c947ca4d9b1196957c0 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/autofill/AutofillPreferences.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/autofill/AutofillPreferences.java
@@ -4,8 +4,6 @@
 
 package org.chromium.chrome.browser.preferences.autofill;
 
-import android.app.Activity;
-import android.content.Context;
 import android.graphics.PorterDuff;
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
@@ -177,22 +175,14 @@ public class AutofillPreferences extends PreferenceFragment
     }
 
     @Override
-    public void onDestroy() {
-        super.onDestroy();
-        PersonalDataManager.getInstance().unregisterDataObserver(this);
-    }
-
-    // TODO: remove this than we only support Build.VERSION_CODES.M and newer.
-    @SuppressWarnings("deprecation")
-    @Override
-    public void onAttach(Activity activity) {
-        super.onAttach(activity);
+    public void onActivityCreated(Bundle savedInstanceState) {
+        super.onActivityCreated(savedInstanceState);
         PersonalDataManager.getInstance().registerDataObserver(this);
     }
 
     @Override
-    public void onAttach(Context context) {
-        super.onAttach(context);
-        PersonalDataManager.getInstance().registerDataObserver(this);
+    public void onDestroyView() {
+        PersonalDataManager.getInstance().unregisterDataObserver(this);
+        super.onDestroyView();
     }
 }