zip: Add ZipReader and rework Unzip() using the new class.

chrome/chrome_common.gypi

 # Copyright (c) 2011 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': 'common',
       'type': 'static_library',
       'variables': {
@@ skipping 217 matching lines @@
         'common/web_apps.cc',
         'common/web_apps.h',
         'common/web_resource/web_resource_unpacker.cc',
         'common/web_resource/web_resource_unpacker.h',
         'common/worker_thread_ticker.cc',
         'common/worker_thread_ticker.h',
         'common/zip.cc',  # Requires zlib directly.
         'common/zip.h',
         'common/zip_internal.cc',
         'common/zip_internal.h',
+        'common/zip_reader.cc',
+        'common/zip_reader.h',
       ],
       'conditions': [
         ['OS=="win"', {
           'include_dirs': [
             '<(DEPTH)/third_party/wtl/include',
           ],
         }],
         ['toolkit_uses_gtk == 1', {
           'dependencies': [
             '../build/linux/system.gyp:gtk',
@@ skipping 179 matching lines @@
         'common/safe_browsing/csd.proto'
       ],
       'variables': {
         'proto_in_dir': 'common/safe_browsing',
         'proto_out_dir': 'chrome/common/safe_browsing',
       },
       'includes': [ '../build/protoc.gypi' ],
     },
   ],
 }