[Offline pages] Updates to background scheduling to use BTS

chrome/android/java/src/org/chromium/chrome/browser/ChromeBackgroundServiceWaiter.java

-// Copyright 2016 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;
-
-import org.chromium.base.Log;
-
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-
-/**
- * Class to wait for a task to complete before releasing control back to the caller.
- */
-public class ChromeBackgroundServiceWaiter {
-    private static final String TAG = "CBSWaiter";
-    /** Synchronization object to control the wait. */
-    private final CountDownLatch mLatch;
-    /** How long to wait for before giving up */
-    private int mWakelockTimeoutSeconds;
-
-    public ChromeBackgroundServiceWaiter(int wakelockTimeoutSeconds) {
-        mWakelockTimeoutSeconds = wakelockTimeoutSeconds;
-        mLatch = new CountDownLatch(1);
-    }
-
-    /**
-     * Wait, blocking the current thread until another thread calls onWaitDone.
-     */
-    public void startWaiting() {
-        try {
-            boolean waitSucceeded = mLatch.await(mWakelockTimeoutSeconds, TimeUnit.SECONDS);
-            if (!waitSucceeded) {
-                Log.d(TAG, "waiting for latch timed out");
-            }
-        } catch (InterruptedException e) {
-            Log.d(TAG, "ChromeBackgroundServiceWaiter interrupted while holding wake lock. " + e);
-        }
-    }
-
-
-    /**
-     * Called when the wait is complete.
-     */
-    public void onWaitDone() {
-        // Release the waited thread to return to the caller, and thus release the wake lock held on
-        // behalf of the Owner.
-        mLatch.countDown();
-    }
-}