Get rid of assumptions about ".nexe" extension.

tests/chrome_extension/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.
 
 # Test loading a NaCl-enabled Chrome Extension.
 
 Import('env')
 
 # BUG(adonovan): test is breaking on ARM.  Disable in haste...
 if env.Bit('target_arm'):
   Return()
 
 
-nexe = 'ppapi_test_example_%s.nexe' % env.get('TARGET_FULLARCH')
+nexe = 'ppapi_test_example_${TARGET_FULLARCH}${PROGSUFFIX}'
 
 # Note: this test uses the nexe, manifest.json, background.html and
 # test_bridge.js, but these files are loaded from the disk as part of the
 # installed Chrome extension and not loaded through the tester's web server.
 # These files need their own install command.
 dest_copy = env.Replicate('$STAGING_DIR/chrome_extension',
                           [env.File('$STAGING_DIR/%s' % nexe),
                            env.File('$STAGING_DIR/ppapi_test_example.nmf'),
                            'background.html',
                            'manifest.json',
                            'test_bridge.js'])
 
 node = env.PPAPIBrowserTester(
     'chrome_extension_test.out',
     url='chrome_extension_test.html',
     extensions=[env.Dir('$STAGING_DIR/chrome_extension')],
     files=[env.File('chrome_extension_test.html')],
     args=['--enable_experimental_js']
     )
 env.Depends(node, dest_copy)
 env.Alias('all_programs', dest_copy)
 
 env.AddNodeToTestSuite(node,
                        ['chrome_browser_tests'],
                        'run_chrome_extension_test',
                        is_flaky=True, # Don't subject Chrome to our problems.
                        is_broken=env.PPAPIBrowserTesterIsBroken())