Add cross-platform API to get the form factor of the device

chrome/chrome_common.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.
 
 {
   'targets': [
     {
       'target_name': 'common',
       'type': 'static_library',
       'variables': {
@@ skipping 96 matching lines @@
         'common/content_settings_pattern.cc',
         'common/content_settings_pattern.h',
         'common/content_settings_pattern_parser.cc',
         'common/content_settings_pattern_parser.h',
         'common/content_settings_types.h',
         'common/crash_keys.cc',
         'common/crash_keys.h',
         'common/custom_handlers/protocol_handler.cc',
         'common/custom_handlers/protocol_handler.h',
         'common/descriptors_android.h',
+        'common/device_form_factor_android.cc',
+        'common/device_form_factor_desktop.cc',
+        'common/device_form_factor_ios.mm',
+        'common/device_form_factor.h',
         'common/dump_without_crashing.cc',
         'common/dump_without_crashing.h',
         'common/encrypted_media_messages_android.h',
         'common/extensions/api/commands/commands_handler.cc',
         'common/extensions/api/commands/commands_handler.h',
         'common/extensions/api/extension_action/action_info.cc',
         'common/extensions/api/extension_action/action_info.h',
         'common/extensions/api/extension_action/browser_action_handler.cc',
         'common/extensions/api/extension_action/browser_action_handler.h',
         'common/extensions/api/extension_action/page_action_handler.cc',
@@ skipping 371 matching lines @@
           ],
           'include_dirs': [
             '<(DEPTH)/breakpad/src',
           ],
         }],
         ['OS!="ios" and chrome_multiple_dll!=1', {
           'dependencies': [
             '<(DEPTH)/webkit/glue/webkit_glue.gyp:glue',
           ],
         }],
+        ['OS=="android" or OS=="ios"', {
+          'sources!': [
+            'common/device_form_factor_desktop.cc'
+          ],
+        }],
         ['OS=="android"', {
           'sources/': [
             ['exclude', '^common/chrome_version_info_posix.cc'],
             ['exclude', '^common/service_'],
           ],
           'sources!': [
             'common/badge_util.cc',
             'common/extensions/api/extension_action/browser_action_handler.cc',
             'common/extensions/api/extension_action/page_action_handler.cc',
             'common/extensions/api/spellcheck/spellcheck_handler.cc',
@@ skipping 270 matching lines @@
         'common/metrics/proto/user_action_event.proto',
       ],
       'variables': {
         'proto_in_dir': 'common/metrics/proto',
         'proto_out_dir': 'chrome/common/metrics/proto',
       },
       'includes': [ '../build/protoc.gypi' ],
     },
   ],
 }