Merge code which extracts assets from APK to file

android_webview/glue/java/src/com/android/webview/chromium/LicenseContentProvider.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 com.android.webview.chromium;
 
 import android.content.ContentProvider;
 import android.content.ContentValues;
 import android.content.res.AssetFileDescriptor;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.ParcelFileDescriptor;
 import android.util.Log;
 
-import java.io.BufferedOutputStream;
+import org.chromium.base.FileUtils;
+
 import java.io.File;
-import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
 
 /**
  * Content provider for the OSS licenses file.
  */
 public class LicenseContentProvider extends ContentProvider {
     public static final String LICENSES_URI_SUFFIX = "LicenseContentProvider/webview_licenses";
     public static final String LICENSES_CONTENT_TYPE = "text/html";
 
     @Override
     public boolean onCreate() {
@@ skipping 10 matching lines @@
             }
         }
         return null;
     }
 
     // This is to work around the known limitation of AssetManager.openFd to refuse
     // opening files that are compressed in the apk file.
     private AssetFileDescriptor extractAsset(String name) throws IOException {
         File extractedFile = new File(getContext().getCacheDir(), name);
         if (!extractedFile.exists()) {
-            InputStream inputStream = null;
-            OutputStream outputStream = null;
-            try {
-                inputStream = getContext().getAssets().open(name);
-                outputStream = new BufferedOutputStream(
-                        new FileOutputStream(extractedFile.getAbsolutePath()));
-                copyStreams(inputStream, outputStream);
-            } finally {
-                if (inputStream != null) inputStream.close();
-                if (outputStream != null) outputStream.close();
-            }
+            FileUtils.extractAsset(getContext(), name, extractedFile);
         }
         ParcelFileDescriptor parcelFd =
                 ParcelFileDescriptor.open(extractedFile, ParcelFileDescriptor.MODE_READ_ONLY);
         if (parcelFd != null) {
             return new AssetFileDescriptor(parcelFd, 0, parcelFd.getStatSize());
         }
         return null;
     }
 
-    private static void copyStreams(InputStream in, OutputStream out) throws IOException {
-        byte[] buffer = new byte[8192];
-        int c;
-        while ((c = in.read(buffer)) != -1) {
-            out.write(buffer, 0, c);
-        }
-    }
-
     @Override
     public String getType(Uri uri) {
         if (uri != null && uri.toString().endsWith(LICENSES_URI_SUFFIX)) {
             return LICENSES_CONTENT_TYPE;
         }
         return null;
     }
 
     @Override
     public int update(Uri uri, ContentValues values, String where,
@@ skipping 10 matching lines @@
     public Uri insert(Uri uri, ContentValues values) {
         throw new UnsupportedOperationException();
     }
 
     @Override
     public Cursor query(Uri uri, String[] projection, String selection,
                         String[] selectionArgs, String sortOrder) {
         throw new UnsupportedOperationException();
     }
 }