Prevent downstream linter warnings.

webrtc/examples/androidapp/src/org/appspot/apprtc/CpuMonitor.java

 /*
  *  Copyright 2015 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 package org.appspot.apprtc;
 
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.os.BatteryManager;
 import android.os.SystemClock;
 import android.util.Log;
-
 import java.io.BufferedReader;
 import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Scanner;
 import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
 /**
  * Simple CPU monitor.  The caller creates a CpuMonitor object which can then
  * be used via sampleCpuUtilization() to collect the percentual use of the
  * cumulative CPU capacity for all CPUs running at their nominal frequency.  3
  * values are generated: (1) getCpuCurrent() returns the use since the last
  * sampleCpuUtilization(), (2) getCpuAvg3() returns the use since 3 prior
  * calls, and (3) getCpuAvgAll() returns the use over all SAMPLE_SAVE_NUMBER
@@ skipping 160 matching lines @@
     return doubleToPercent(frequencyScale.getAverage());
   }
 
   private void scheduleCpuUtilizationTask() {
     if (executor != null) {
       executor.shutdownNow();
       executor = null;
     }
 
     executor = Executors.newSingleThreadScheduledExecutor();
-    executor.scheduleAtFixedRate(new Runnable() {
+    @SuppressWarnings("unused") // Prevent downstream linter warnings.
+    Future<?> possiblyIgnoredError = executor.scheduleAtFixedRate(new Runnable() {
       @Override
       public void run() {
         cpuUtilizationTask();
       }
     }, 0, CPU_STAT_SAMPLE_PERIOD_MS, TimeUnit.MILLISECONDS);
   }
 
   private void cpuUtilizationTask() {
     boolean cpuMonitorAvailable = sampleCpuUtilization();
     if (cpuMonitorAvailable
@@ skipping 283 matching lines @@
     } catch (FileNotFoundException e) {
       Log.e(TAG, "Cannot open /proc/stat for reading", e);
       return null;
     } catch (IOException e) {
       Log.e(TAG, "Problems reading /proc/stat", e);
       return null;
     }
     return new ProcStat(userTime, systemTime, idleTime);
   }
 }