Cancel the request when URLLoader is gone

content/browser/loader/url_loader_factory_impl_unittest.cc

 // 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.
 
 #include "content/browser/loader/url_loader_factory_impl.h"
 
 #include <memory>
 #include <string>
 #include <utility>
 
@@ skipping 241 matching lines @@
 
   client.RunUntilComplete();
   rdh_.SetDelegate(nullptr);
 
   ASSERT_FALSE(client.has_received_response());
   ASSERT_FALSE(client.response_body().is_valid());
 
   EXPECT_EQ(net::ERR_ABORTED, client.completion_status().error_code);
 }
 
+// Cancel the request via URLLoader.
+TEST_P(URLLoaderFactoryImplTest, CancelFromRenderer) {
+  constexpr int32_t kRoutingId = 81;
+  constexpr int32_t kRequestId = 28;
+  NavigationResourceThrottle::set_ui_checks_always_succeed_for_testing(true);
+  mojom::URLLoaderPtr loader;
+  base::FilePath root;
+  PathService::Get(DIR_TEST_DATA, &root);
+  net::URLRequestMockHTTPJob::AddUrlHandlers(root,
+                                             BrowserThread::GetBlockingPool());
+  ResourceRequest request;
+  TestURLLoaderClient client;
+  // Assume the file contents is small enough to be stored in the data pipe.
+  request.url = net::URLRequestMockHTTPJob::GetMockUrl("hello.html");
+  request.method = "GET";
+  request.is_main_frame = true;
+  factory_->CreateLoaderAndStart(mojo::GetProxy(&loader), kRoutingId,
+                                 kRequestId, request,
+                                 client.CreateInterfacePtrAndBind());
+
+  ASSERT_FALSE(client.has_received_response());
+  ASSERT_FALSE(client.response_body().is_valid());
+  ASSERT_FALSE(client.has_received_completion());
+
+  loader->Cancel();
+  client.RunUntilComplete();

[mmenke, 2016/11/01 13:52:32]

Hrm...I wonder...Do we want to promise an OnComplete call on cancellation?  We
do currently send messages in this case, but ResourceDispatcher has already
cleaned up the request by then, anyways.

[yhirano, 2016/11/01 14:24:25]

Yeah, I'm not particularly interested in receiving a OnComplete method, but it's
the simplest way to detect that the loading is aborted as far as I know.

[mmenke, 2016/11/01 14:27:54]

I'm thinking it may be simplest to tear down the loader in this case, excluding
the usual download/detachable cases.

One other question:  Is there some way to have mojo automatically trigger a
cancel if the URLLoader is torn town?

[mmenke, 2016/11/01 14:30:05]

Also, if we're not going to promise an OnComplete call (And I'd rather not),
then I'd like to ensure we don't call it from the start.

[yhirano, 2016/11/02 06:02:56]

Done.

[yhirano, 2016/11/02 06:02:56]

Hm, I didn't think about that. PS4 removes Cancel from the mojom file. What do
you think?

+
+  EXPECT_EQ(net::ERR_ABORTED, client.completion_status().error_code);
+}
+
 INSTANTIATE_TEST_CASE_P(URLLoaderFactoryImplTest,
                         URLLoaderFactoryImplTest,
                         ::testing::Values(128, 32 * 1024));
 
 }  // namespace
 
 }  // namespace content