Disable a PPAPI crash test under Valgrind.

ppapi/native_client/tests/ppapi_browser/bad/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.
 #
 # Tests fatal errors that occur during loading.
 # (See ppapi_browser/crash for fatal errors that occur after loading).
 # TODO(polina): rename the directory and browser test to bad_load
 #
 # Manual testing with localhost:5103/scons-out/.../staging/ppapi_bad.html:
@@ skipping 49 matching lines @@
 
 node = env.PPAPIBrowserTester(
     'ppapi_bad_browser_test.out',
     url='ppapi_bad.html',
     nmfs=nmfs,
     files=[env.File(f) for f in ppapi_bad_files],
     args=['--allow_404'])
 
 # This test is failing on Windows:
 #   crbug.com/98720
+# This test is failing on Valgrind because of multiple nexes.
 env.AddNodeToTestSuite(node,
                        ['chrome_browser_tests'],
                        'run_ppapi_bad_browser_test',
                        is_broken=env.PPAPIBrowserTesterIsBroken() or
-                                 env.Bit('host_windows'))
+                                 env.Bit('host_windows') or 
+                                 env.Bit('running_on_valgrind'))
 
 
 # Bad nexe tests that won't work in PNaCl (native)
 # For example, partly_invalid.nexe has inline assembly in its source files.
 nacltest_js = env.File('${SCONSTRUCT_DIR}/tools/browser_tester/browserdata/' +
                        'nacltest.js')
 partly_invalid = env.File('${STAGING_DIR}/partly_invalid${PROGSUFFIX}')
 nmf = '${TEST_DIR}/partly_invalid.nmf'
 if not env.Bit('nacl_glibc'):
   ppapi_bad_native_files = [
@@ skipping 29 matching lines @@
           'golden': '${TEST_DIR}/ppapi_bad_native_glibc.stderr'}
       )
 
 env.AddNodeToTestSuite(node,
                        ['chrome_browser_tests'],
                        'run_ppapi_bad_native_test',
                        is_broken=env.PPAPIBrowserTesterIsBroken() or
                                  env.Bit('bitcode'))