Pass lsan GYP variable to swarming's test_env so that we can disable the sandbox when it's set.

chrome/browser_tests.isolate

 # Copyright (c) 2012 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.
 {
   'includes': [
     'chrome.isolate',
   ],
   'conditions': [
     ['OS=="linux"', {
       'variables': {
         'command': [
           '../testing/xvfb.py',
           '<(PRODUCT_DIR)',
           '<(PRODUCT_DIR)/browser_tests<(EXECUTABLE_SUFFIX)',
           '--test-launcher-bot-mode',
+          '--lsan=<(lsan)',
         ],
         'isolate_dependency_tracked': [
           '../testing/xvfb.py',
           '<(PRODUCT_DIR)/libclearkeycdm.so',
           '<(PRODUCT_DIR)/libclearkeycdmadapter.so',
           '<(PRODUCT_DIR)/libppapi_tests.so',
         ],
       },
     }],
     ['OS=="linux" and use_ozone==0', {
@@ skipping 152 matching lines @@
           '../ui/file_manager/file_manager/',
           '../ui/webui/resources/js/',
           '<(PRODUCT_DIR)/chromevox_test_data/',
           '<(PRODUCT_DIR)/locales/',
           '<(PRODUCT_DIR)/resources/chromeos/',
         ],
       },
     }],
   ],
 }