xcode: Add xcassets = folder.assetcatalog to extension_map

pylib/gyp/xcodeproj_file.py

 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Xcode project file generator.
 
 This module is both an Xcode project file generator and a documentation of the
 Xcode project file format.  Knowledge of the project file format was gained
 based on extensive experience with Xcode, and by making changes to projects in
 Xcode.app and observing the resultant changes in the associated project files.
@@ skipping 1491 matching lines @@
         'plist':       'text.plist.xml',
         'pm':          'text.script.perl',
         'png':         'image.png',
         'py':          'text.script.python',
         'r':           'sourcecode.rez',
         'rez':         'sourcecode.rez',
         's':           'sourcecode.asm',
         'storyboard':  'file.storyboard',
         'strings':     'text.plist.strings',
         'ttf':         'file',
+        'xcassets':    'folder.assetcatalog',
         'xcconfig':    'text.xcconfig',
         'xcdatamodel': 'wrapper.xcdatamodel',
         'xib':         'file.xib',
         'y':           'sourcecode.yacc',
       }
 
       prop_map = {
         'dart':        'explicitFileType',
         'gyp':         'explicitFileType',
         'gypi':        'explicitFileType',
@@ skipping 1357 matching lines @@
       self._XCPrint(file, 0, '/* Begin ' + class_name + ' section */\n')
       for object in sorted(objects_by_class[class_name],
                            cmp=lambda x, y: cmp(x.id, y.id)):
         object.Print(file)
       self._XCPrint(file, 0, '/* End ' + class_name + ' section */\n')
 
     if self._should_print_single_line:
       self._XCPrint(file, 0, '}; ')
     else:
       self._XCPrint(file, 1, '};\n')