[Blob] BlobReader class & tests, and removal of all redundant reading.

content/content_tests.gypi

 # Copyright (c) 2013 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.
 
 {
   'variables': {
     'layouttest_support_content_sources': [
       'public/test/layouttest_support.h',
       'public/test/nested_message_pump_android.cc',
       'public/test/nested_message_pump_android.h',
@@ skipping 365 matching lines @@
       'browser/dom_storage/dom_storage_context_impl_unittest.cc',
       'browser/dom_storage/dom_storage_database_unittest.cc',
       'browser/dom_storage/session_storage_database_unittest.cc',
       'browser/download/base_file_unittest.cc',
       'browser/download/download_file_unittest.cc',
       'browser/download/download_item_impl_unittest.cc',
       'browser/download/download_manager_impl_unittest.cc',
       'browser/download/file_metadata_unittest_linux.cc',
       'browser/download/rate_estimator_unittest.cc',
       'browser/download/save_package_unittest.cc',
+      'browser/fileapi/blob_reader_unittest.cc',
       'browser/fileapi/blob_storage_context_unittest.cc',
       'browser/fileapi/blob_url_request_job_unittest.cc',
       'browser/fileapi/copy_or_move_file_validator_unittest.cc',
       'browser/fileapi/copy_or_move_operation_delegate_unittest.cc',
       'browser/fileapi/dragged_file_util_unittest.cc',
       'browser/fileapi/external_mount_points_unittest.cc',
       'browser/fileapi/file_system_context_unittest.cc',
       'browser/fileapi/file_system_dir_url_request_job_unittest.cc',
       'browser/fileapi/file_system_file_stream_reader_unittest.cc',
       'browser/fileapi/file_system_operation_impl_unittest.cc',
@@ skipping 1732 matching lines @@
             ],
           },
           'includes': [
             '../build/host_jar.gypi',
           ],
         },
       ],
     }],
   ],
 }