gn_helpers: Roll GN helpers again to pick up whitespace fix.

And update simple chrome to use the new API.

BUG=chromium:937821
TEST=unittest
TEST=simplechrome'ed locally

Change-Id: If4ea1e2ff882f12b8204a8721b43e043e9893ff6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2233279
Tested-by: Ben Pastene <bpastene@chromium.org>
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
diff --git a/cli/cros/cros_chrome_sdk.py b/cli/cros/cros_chrome_sdk.py
index 8428d27..f155c8a 100644
--- a/cli/cros/cros_chrome_sdk.py
+++ b/cli/cros/cros_chrome_sdk.py
@@ -1031,7 +1031,9 @@
       logging.warning('No args.gn file: %s', gn_args_file_path)
       return True
 
-    old_gn_args = gn_helpers.FromGNArgs(osutils.ReadFile(gn_args_file_path))
+    parser = gn_helpers.GNValueParser(osutils.ReadFile(gn_args_file_path),
+                                      checkout_root=self.options.chrome_src)
+    old_gn_args = parser.ParseArgs()
     if new_gn_args == old_gn_args:
       return False
 
diff --git a/third_party/gn_helpers/README.chromium b/third_party/gn_helpers/README.chromium
index c8db168..6abc258 100644
--- a/third_party/gn_helpers/README.chromium
+++ b/third_party/gn_helpers/README.chromium
@@ -2,7 +2,7 @@
 Short Name: gn_helpers
 URL: https://chromium.googlesource.com/chromium/src/+/master/build/gn_helpers.py
 Version: 0
-Revision: b52227fdc93299e95e0df9dd8693446af7f5368f
+Revision: b75f8eca53df514c5b9ff8ee3252793a32da92e3
 License: BSD
 Security Critical: no
 
diff --git a/third_party/gn_helpers/gn_helpers.py b/third_party/gn_helpers/gn_helpers.py
index f003c4b..9e24c79 100644
--- a/third_party/gn_helpers/gn_helpers.py
+++ b/third_party/gn_helpers/gn_helpers.py
@@ -284,6 +284,7 @@
       val = self._ParseAllowTrailing()
       self.ConsumeWhitespace()
       self.ConsumeComment()
+      self.ConsumeWhitespace()
       d[ident] = val
 
     return d