Merge java_staging/src into java/src.

chrome/android/java/src/org/chromium/chrome/browser/util/NonThreadSafe.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.chrome.browser.util;
 
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.SuppressFBWarnings;
 
 /**
@@ skipping 25 matching lines @@
     @SuppressFBWarnings("CHROMIUM_SYNCHRONIZED_METHOD")
     public synchronized boolean calledOnValidThread() {
         ensureThreadIdAssigned();
         return mThreadId.equals(Thread.currentThread().getId());
     }
 
     private void ensureThreadIdAssigned() {
         if (mThreadId == null) mThreadId = Thread.currentThread().getId();
     }
 }