Update to newer Android Lint and suppress new Lint errors

components/sync/android/java/src/org/chromium/components/sync/AndroidSyncSettings.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.components.sync;
 
 import android.accounts.Account;
+import android.annotation.SuppressLint;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.SyncStatusObserver;
 import android.os.Bundle;
 import android.os.StrictMode;
 
 import org.chromium.base.Callback;
 import org.chromium.base.ObserverList;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.components.signin.AccountManagerHelper;
@@ skipping 15 matching lines @@
  */
 @ThreadSafe
 public class AndroidSyncSettings {
     public static final String TAG = "AndroidSyncSettings";
 
     /**
      * Lock for ensuring singleton instantiation across threads.
      */
     private static final Object CLASS_LOCK = new Object();
 
+    @SuppressLint("StaticFieldLeak")
     private static AndroidSyncSettings sInstance;
 
     private final Object mLock = new Object();
 
     private final String mContractAuthority;
 
     private final Context mApplicationContext;
 
     private final SyncContentResolverDelegate mSyncContentResolverDelegate;
 
@@ skipping 262 matching lines @@
     private void notifyObservers() {
         for (AndroidSyncSettingsObserver observer : mObservers) {
             observer.androidSyncSettingsChanged();
         }
     }
 
     private String getContractAuthority() {
         return mApplicationContext.getPackageName();
     }
 }