Refactor FeedbackData and add tests.

components/feedback.gypi

 # Copyright 2014 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': 'feedback_component',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../content/content.gyp:content_common',
         '../net/net.gyp:net',
         '../third_party/zlib/google/zip.gyp:zip',
         'components.gyp:keyed_service_core',
         'feedback_proto',
       ],
       'include_dirs': [
         '..',
       ],
       'defines': [
       ],
       'sources': [
+        'feedback/feedback_common.cc',
+        'feedback/feedback_common.h',
         'feedback/feedback_data.cc',
         'feedback/feedback_data.h',
         'feedback/feedback_report.cc',
         'feedback/feedback_report.h',
         'feedback/feedback_switches.cc',
         'feedback/feedback_switches.h',
         'feedback/feedback_uploader.cc',
         'feedback/feedback_uploader.h',
         'feedback/feedback_uploader_chrome.cc',
         'feedback/feedback_uploader_chrome.h',
@@ skipping 21 matching lines @@
         'feedback/proto/web.proto',
       ],
       'variables': {
         'proto_in_dir': 'feedback/proto',
         'proto_out_dir': 'components/feedback/proto',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }