Pass isolate output dir to gtest-parallel-wrapper.py

DEPS

 # This file contains dependencies for WebRTC.
 
 vars = {
   'chromium_git': 'https://chromium.googlesource.com',
   'chromium_revision': '496a750d382e5ff646318d04f85e8bcd02a48ff9',
   'boringssl_git': 'https://boringssl.googlesource.com',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.
   'swarming_revision': 'ebc8dab6f8b8d79ec221c94de39a921145abd404',
@@ skipping 79 matching lines @@
     Var('chromium_git') + '/external/gyp.git' + '@' + 'e7079f0e0e14108ab0dba58728ff219637458563',
    'src/tools/swarming_client':
      Var('chromium_git') + '/external/swarming.client.git' + '@' +  Var('swarming_revision'),
 
   # WebRTC-only dependencies (not present in Chromium).
   'src/third_party/gflags':
     Var('chromium_git') + '/external/webrtc/deps/third_party/gflags' + '@' + '892576179b45861b53e04a112996a738309cf364',
   'src/third_party/gflags/src':
     Var('chromium_git') + '/external/github.com/gflags/gflags' + '@' + '03bebcb065c83beff83d50ae025a55a4bf94dfca',
   'src/third_party/gtest-parallel':
-    Var('chromium_git') + '/external/webrtc/deps/third_party/gtest-parallel' + '@' + '8768563f5c580f8fc416a13c35c8f23b8a602821',
+    Var('chromium_git') + '/external/webrtc/deps/third_party/gtest-parallel' + '@' + '1dad0e9f6d82ff994130b529d7d814b40eb32b0e',
 }
 
 deps_os = {
   'android': {
     'src/third_party/android_tools':
       Var('chromium_git') + '/android_tools.git' + '@' + 'b43a6a289a7588b1769814f04dd6c7d7176974cc',
     'src/third_party/ced/src':
       Var('chromium_git') + '/external/github.com/google/compact_enc_det.git' + '@' + '368a9cc09ad868a3d28f0b5ad4a733f263c46409',
     'src/third_party/icu':
       Var('chromium_git') + '/chromium/deps/icu.git' + '@' + '9cd2828740572ba6f694b9365236a8356fd06147',
@@ skipping 416 matching lines @@
   },
 ]
 
 recursedeps = [
   # buildtools provides clang_format, libc++, and libc++abi.
   'src/buildtools',
   # android_tools manages the NDK.
   'src/third_party/android_tools',
 ]