[Cronet] Unregister NetLog observer during shutdown

components/cronet/android/cronet_url_request_context_adapter.h

 // 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.
 
 #ifndef COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_CONTEXT_ADAPTER_H_
 #define COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_CONTEXT_ADAPTER_H_
 
 #include <jni.h>
 #include <stdint.h>
 
@@ skipping 143 matching lines @@
   void OnRTTObservation(int32_t rtt_ms,
                         const base::TimeTicks& timestamp,
                         net::NetworkQualityObservationSource source) override;
 
   // net::NetworkQualityEstimator::ThroughputObserver implementation.
   void OnThroughputObservation(
       int32_t throughput_kbps,
       const base::TimeTicks& timestamp,
       net::NetworkQualityObservationSource source) override;
 
+  // Helper method to stop NetLog logging to file. This can be called on any
+  // thread. This will flush any remaining writes to disk.
+  void StopNetLogHelper();
+
   // Network thread is owned by |this|, but is destroyed from java thread.
   base::Thread* network_thread_;
 
   // File thread should be destroyed last.
   std::unique_ptr<base::Thread> file_thread_;
 
   // |write_to_file_observer_| should only be accessed with
   // |write_to_file_observer_lock_|.
   std::unique_ptr<net::WriteToFileNetLogObserver> write_to_file_observer_;
   base::Lock write_to_file_observer_lock_;
@@ skipping 28 matching lines @@
 #if defined(DATA_REDUCTION_PROXY_SUPPORT)
   std::unique_ptr<CronetDataReductionProxy> data_reduction_proxy_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(CronetURLRequestContextAdapter);
 };
 
 }  // namespace cronet
 
 #endif  // COMPONENTS_CRONET_ANDROID_CRONET_URL_REQUEST_CONTEXT_ADAPTER_H_