Get rid of assumptions about ".nexe" extension.

tests/ppapi_example_font/nacl.scons

 # -*- python -*-
 # Copyright (c) 2011 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This is a Pepper font example from ppapi/examples/font.
 
 Import('env')
 
 env.Prepend(CPPDEFINES=['XP_UNIX'])
 
 # Adjust compiler flags to the more forgiving standards used in
 # ppapi/examples/*.
 env.FilterOut(CCFLAGS=['-Werror', '-pedantic'])
 env.Append(CCFLAGS=['-Wformat=0'])
 
-nexe_name = 'ppapi_example_font_%s.nexe' % env.get('TARGET_FULLARCH')
+nexe_name = 'ppapi_example_font_${TARGET_FULLARCH}'
 nexe = env.ComponentProgram(
     nexe_name,
     ['$SOURCE_ROOT/ppapi/examples/font/simple_font.cc'],
     EXTRA_LIBS=['${PPAPI_LIBS}', 'ppapi_cpp'])
 
 # Note that the html is required to run this program.
 env.Publish(nexe_name, 'run',
             ['ppapi_example_font.html', 'ppapi_example_font.nmf'])
 
 test = env.PPAPIBrowserTester('ppapi_example_font_test.out',
                               url='ppapi_example_font.html',
                               files=env.ExtractPublishedFiles(nexe_name),
                               args=['--enable_experimental_js'])
 
 env.AddNodeToTestSuite(test,
                        ['chrome_browser_tests'],
                        'run_ppapi_example_font_test',
                        is_broken=env.PPAPIBrowserTesterIsBroken())