Fix strict mode violation in TabPersistentStore.cleanupPersistentData()

base/android/java/src/org/chromium/base/PathUtils.java

 // Copyright 2012 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.base;
 
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.os.AsyncTask;
 import android.os.Environment;
 import android.os.StrictMode;
 import android.os.SystemClock;
+import android.support.annotation.WorkerThread;
 
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.MainDex;
 import org.chromium.base.metrics.RecordHistogram;
 
 import java.io.File;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
 /**
  * This class provides the path related methods for the native library.
  */
 @MainDex
 public abstract class PathUtils {
     private static final String THUMBNAIL_DIRECTORY = "textures";
 
     private static final int DATA_DIRECTORY = 0;
     private static final int DATABASE_DIRECTORY = 1;
     private static final int CACHE_DIRECTORY = 2;
     private static final int NUM_DIRECTORIES = 3;
     private static AsyncTask<String, Void, String[]> sDirPathFetchTask;
 
     private static File sThumbnailDirectory;
+    private static Object sLazyInitLock = new Object();

[gone, 2016/02/18 17:45:35]

private static final?  Can't imagine ever recreating the lock.

[agrieve, 2016/02/23 21:28:38]

Deleted in favour of using sDirPathFetchTask

 
     // Prevent instantiation.
     private PathUtils() {}
 
     /**
      * Starts an asynchronous task to fetch the path of the directory where private data is to be
      * stored by the application.
      *
      * @param suffix The private data directory suffix.
      * @see Context#getDir(String, int)
@@ skipping 50 matching lines @@
     /**
      * @return the cache directory.
      */
     @SuppressWarnings("unused")
     @CalledByNative
     public static String getCacheDirectory(Context appContext) {
         assert sDirPathFetchTask != null : "setDataDirectorySuffix must be called first.";
         return getDirectoryPath(CACHE_DIRECTORY);
     }
 
+    @WorkerThread
     public static File getThumbnailCacheDirectory(Context appContext) {
+        ThreadUtils.assertOnFileThread();
         if (sThumbnailDirectory == null) {
-            // Temporarily allowing disk access while fixing. TODO: http://crbug.com/473356
-            StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
-            StrictMode.allowThreadDiskWrites();
-            try {
-                long time = SystemClock.elapsedRealtime();
-                sThumbnailDirectory = appContext.getDir(THUMBNAIL_DIRECTORY, Context.MODE_PRIVATE);
-                RecordHistogram.recordTimesHistogram("Android.StrictMode.ThumbnailCacheDir",
-                        SystemClock.elapsedRealtime() - time, TimeUnit.MILLISECONDS);
-            } finally {
-                StrictMode.setThreadPolicy(oldPolicy);
+            synchronized (sLazyInitLock) {
+                if (sThumbnailDirectory == null) {
+                    long time = SystemClock.elapsedRealtime();
+                    sThumbnailDirectory =
+                            appContext.getDir(THUMBNAIL_DIRECTORY, Context.MODE_PRIVATE);
+                    RecordHistogram.recordTimesHistogram("Android.StrictMode.ThumbnailCacheDir",
+                            SystemClock.elapsedRealtime() - time, TimeUnit.MILLISECONDS);
+                }
             }
         }
         return sThumbnailDirectory;
     }
 
     @CalledByNative
     public static String getThumbnailCacheDirectoryPath(Context appContext) {
         return getThumbnailCacheDirectory(appContext).getAbsolutePath();
     }
 
@@ skipping 35 matching lines @@
 
     /**
      * @return the external storage directory.
      */
     @SuppressWarnings("unused")
     @CalledByNative
     public static String getExternalStorageDirectory() {
         return Environment.getExternalStorageDirectory().getAbsolutePath();
     }
 }