Avoid issuing a Read() after draining a request.

chrome/browser/download/download_browsertest.cc

 // Copyright (c) 2012 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 <sstream>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 3194 matching lines @@
 
   // No errors this time. The download should complete successfully.
   EXPECT_FALSE(completion_observer->IsFinished());
   completion_observer->StartObserving();
   download->Resume();
   completion_observer->WaitForFinished();
   EXPECT_EQ(DownloadItem::COMPLETE, download->GetState());
 
   EXPECT_FALSE(DidShowFileChooser());
 }
+
+// The file empty.bin is served with a MIME type of application/octet-stream.
+// The content body is empty. Make sure this case is handled properly and we
+// don't regress on http://crbug.com/320394.
+IN_PROC_BROWSER_TEST_F(DownloadTest, DownloadTest_GZipWithNoContent) {
+  ASSERT_TRUE(test_server()->Start());
+  GURL url(test_server()->GetURL("files/downloads/empty.bin"));
+  // Downloading the same URL twice causes the second request to be served from
+  // cached (with a high probability). This test verifies that that doesn't
+  // happen regardless of whether the request is served via the cache or from
+  // the network.
+  DownloadAndWait(browser(), url);
+  DownloadAndWait(browser(), url);
+}