Expose startNetLog / stopNetLog from HttpUrlRequestFactory.

components/cronet/android/java/src/org/chromium/net/HttpUrlRequestFactory.java

 // Copyright 2014 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.net;
 
 import android.content.Context;
 import android.util.Log;
 
 import java.lang.reflect.Constructor;
@@ skipping 41 matching lines @@
             int requestPriority, Map<String, String> headers,
             HttpUrlRequestListener listener);
 
     /**
      * Creates a new request intended for streaming.
      */
     public abstract HttpUrlRequest createRequest(String url,
             int requestPriority, Map<String, String> headers,
             WritableByteChannel channel, HttpUrlRequestListener listener);
 
+    /**
+     * Starts NetLog logging to a file named |fileName| in the
+     * application temporary directory. |fileName| must not be empty. Log level
+     * is LOG_ALL_BUT_BYTES. If the file exists it is truncated before starting.
+     * If actively logging the call is ignored.
+     */
+    public void startNetLogToFile(String fileName) {

[xunjieli, 2014/09/26 18:22:45]

Empty functions here look a little weird. Can we make them abstract or throw
unimplemented exception? 

[mef, 2014/09/26 18:33:49]

Done.

+    }
+
+    /**
+     * Stops NetLog logging and flushes file to disk. If a logging session is
+     * not in progress this call is ignored.
+     */
+    public void stopNetLog() {
+    }
+
     private static HttpUrlRequestFactory createChromiumFactory(
             Context context, HttpUrlRequestFactoryConfig config) {
         HttpUrlRequestFactory factory = null;
         try {
             Class<? extends HttpUrlRequestFactory> factoryClass =
                     HttpUrlRequestFactory.class.getClassLoader().
                             loadClass(CHROMIUM_URL_REQUEST_FACTORY).
                             asSubclass(HttpUrlRequestFactory.class);
             Constructor<? extends HttpUrlRequestFactory> constructor =
                     factoryClass.getConstructor(
                             Context.class, HttpUrlRequestFactoryConfig.class);
             HttpUrlRequestFactory chromiumFactory =
                     constructor.newInstance(context, config);
             if (chromiumFactory.isEnabled()) {
                 factory = chromiumFactory;
             }
         } catch (ClassNotFoundException e) {
             // Leave as null
         } catch (Exception e) {
             throw new IllegalStateException(
                     "Cannot instantiate: " +
                     CHROMIUM_URL_REQUEST_FACTORY,
                     e);
         }
         return factory;
     }
 }