Fix an issue that we didn't clean url request properly.

content/browser/download/download_file_impl.cc

Index: content/browser/download/download_file_impl.cc
diff --git a/content/browser/download/download_file_impl.cc b/content/browser/download/download_file_impl.cc
index f65534b2c0783a97d5f587a70711d2d625077644..8e6941676760984230e6337b48363a8d1ff42481 100644
--- a/content/browser/download/download_file_impl.cc
+++ b/content/browser/download/download_file_impl.cc
@@ -128,12 +128,14 @@ DownloadFileImpl::~DownloadFileImpl() {
 }
 
 void DownloadFileImpl::Initialize(
-    const InitializeCallback& callback,
+    const InitializeCallback& initialize_callback,
+    const CancelRequestCallback& cancel_request_callback,
     const DownloadItem::ReceivedSlices& received_slices) {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
 
   update_timer_.reset(new base::RepeatingTimer());
   int64_t bytes_so_far = 0;
+  cancel_request_callback_ = cancel_request_callback;
   received_slices_ = received_slices;
   if (IsSparseFile()) {
     for (const auto& received_slice : received_slices_) {
@@ -148,8 +150,8 @@ void DownloadFileImpl::Initialize(
       save_info_->hash_of_partial_file, std::move(save_info_->hash_state),
       IsSparseFile());
   if (result != DOWNLOAD_INTERRUPT_REASON_NONE) {
-    BrowserThread::PostTask(
-        BrowserThread::UI, FROM_HERE, base::Bind(callback, result));
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                            base::Bind(initialize_callback, result));
     return;
   }
 
@@ -160,8 +162,8 @@ void DownloadFileImpl::Initialize(
   SendUpdate();
 
   BrowserThread::PostTask(
-      BrowserThread::UI, FROM_HERE, base::Bind(
-          callback, DOWNLOAD_INTERRUPT_REASON_NONE));
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(initialize_callback, DOWNLOAD_INTERRUPT_REASON_NONE));
 
   // Initial pull from the straw from all source streams.
   for (auto& source_stream : source_streams_)
@@ -328,6 +330,8 @@ void DownloadFileImpl::RenameWithRetryInternal(
     SendUpdate();
 
     // Null out callback so that we don't do any more stream processing.
+    // The request that writes to the pipe should be canceled after
+    // the download being interrupted.
     for (auto& stream : source_streams_) {
       ByteStreamReader* stream_reader = stream.second->stream_reader();
       if (stream_reader)
@@ -469,6 +473,8 @@ void DownloadFileImpl::StreamActive(SourceStream* source_stream) {
     // Signal successful completion or termination of the current stream.
     source_stream->stream_reader()->RegisterCallback(base::Closure());
     source_stream->set_finished(true);
+    if (should_terminate)
+      CancelRequestOnUIThread(source_stream->offset());
     if (source_stream->length() == DownloadSaveInfo::kLengthFullContent) {
       SetPotentialFileLength(source_stream->offset() +
                              source_stream->bytes_written());
@@ -641,6 +647,7 @@ void DownloadFileImpl::HandleStreamError(SourceStream* source_stream,
           DCHECK_EQ(stream.second->bytes_written(), 0);
           stream.second->stream_reader()->RegisterCallback(base::Closure());
           stream.second->set_finished(true);
+          CancelRequestOnUIThread(stream.second->offset());
           num_active_streams_--;
         }
       }
@@ -680,6 +687,13 @@ DownloadFileImpl::SourceStream* DownloadFileImpl::FindPrecedingNeighbor(
   return ret;
 }
 
+void DownloadFileImpl::CancelRequestOnUIThread(int64_t offset) {

[asanka, 2017/04/21 15:09:28]

Nit : The naming convention is to name the function based on which thread it
runs on if it differs from surrounding code. In this case the function runs on
the IO thread. That reduces the chance of accidentally calling a function that
needs to be scheduled on a different thread.

In this case, you could just call this CancelRequest() since it shares the
thread affinity with the surrounding code.

[xingliu, 2017/04/22 00:07:23]

Done. Thanks.

+  if (!cancel_request_callback_.is_null()) {
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                            base::Bind(cancel_request_callback_, offset));
+  }
+}
+
 void DownloadFileImpl::DebugStates() const {
   DVLOG(1) << "### Debugging DownloadFile states:";
   DVLOG(1) << "Total source stream count = " << source_streams_.size();