Cancel the request when URLLoader is gone

content/browser/loader/mojo_async_resource_handler.h

 // Copyright 2016 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 CONTENT_BROWSER_LOADER_MOJO_ASYNC_RESOURCE_HANDLER_H_
 #define CONTENT_BROWSER_LOADER_MOJO_ASYNC_RESOURCE_HANDLER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 50 matching lines @@
   bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
                   int* buf_size,
                   int min_size) override;
   bool OnReadCompleted(int bytes_read, bool* defer) override;
   void OnResponseCompleted(const net::URLRequestStatus& status,
                            bool* defer) override;
   void OnDataDownloaded(int bytes_downloaded) override;
 
   // mojom::URLLoader implementation
   void FollowRedirect() override;
-  void Cancel() override;
 
   void ResumeForTesting();
   static void SetAllocationSizeForTesting(size_t size);
   static constexpr size_t kDefaultAllocationSize = 512 * 1024;
 
  protected:
   // These functions can be overriden only for tests.
   virtual MojoResult BeginWrite(void** data, uint32_t* available);
   virtual MojoResult EndWrite(uint32_t written);
 
  private:
   class SharedWriter;
   class WriterIOBuffer;
 
   // This funcion copies data stored in |buffer_| to |shared_writer_| and
   // resets |buffer_| to a WriterIOBuffer when all bytes are copied. Returns
   // true when done successfully.
   bool CopyReadDataToDataPipe(bool* defer);
   // Allocates a WriterIOBuffer and set it to |*buf|. Returns true when done
   // successfully.
   bool AllocateWriterIOBuffer(scoped_refptr<net::IOBufferWithSize>* buf,
                               bool* defer);
 
   void Resume();
   void OnDefer();
   bool CheckForSufficientResource();
   void OnWritable(MojoResult result);
+  void Cancel();
 
   ResourceDispatcherHostImpl* rdh_;
   mojo::Binding<mojom::URLLoader> binding_;
 
   bool has_checked_for_sufficient_resources_ = false;
   bool sent_received_response_message_ = false;
   bool is_using_io_buffer_not_from_writer_ = false;
   bool did_defer_ = false;
   base::TimeTicks response_started_ticks_;
 
   mojo::Watcher handle_watcher_;
   std::unique_ptr<mojom::URLLoader> url_loader_;
   mojom::URLLoaderClientPtr url_loader_client_;
   scoped_refptr<net::IOBufferWithSize> buffer_;
   size_t buffer_offset_ = 0;
   size_t buffer_bytes_read_ = 0;
   scoped_refptr<SharedWriter> shared_writer_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoAsyncResourceHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_MOJO_ASYNC_RESOURCE_HANDLER_H_