Use ByteStream in downloads system to decouple source and sink.

content/content_tests.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'test_support_content',
       'type': 'static_library',
       'defines!': ['CONTENT_IMPLEMENTATION'],
@@ skipping 202 matching lines @@
         'browser/accessibility/browser_accessibility_manager_unittest.cc',
         'browser/accessibility/browser_accessibility_win_unittest.cc',
         'browser/appcache/chrome_appcache_service_unittest.cc',
         'browser/browser_thread_unittest.cc',
         'browser/browser_url_handler_impl_unittest.cc',
         'browser/child_process_security_policy_unittest.cc',
         'browser/debugger/devtools_manager_unittest.cc',
         'browser/device_orientation/provider_unittest.cc',
         'browser/download/base_file_unittest.cc',
         'browser/download/byte_stream_unittest.cc',
-        'browser/download/download_buffer_unittest.cc',
         'browser/download/download_file_manager_unittest.cc',
         'browser/download/download_file_unittest.cc',
         'browser/download/download_id_unittest.cc',
         'browser/download/download_item_impl_unittest.cc',
         'browser/download/download_manager_impl_unittest.cc',
         'browser/download/save_package_unittest.cc',
         'browser/gamepad/gamepad_provider_unittest.cc',
         'browser/geolocation/device_data_provider_unittest.cc',
         'browser/geolocation/geolocation_provider_unittest.cc',
         'browser/geolocation/gps_location_provider_unittest_linux.cc',
@@ skipping 353 matching lines @@
               '<(PRODUCT_DIR)/lib.java/chromium_base.jar',
               '<(PRODUCT_DIR)/lib.java/chromium_content.jar',
             ],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }