Fix gn bootstrap

BUG=827899
R=dpranke

Change-Id: Idb5832232d46ffda9df2d540523031a9edfdad44
Reviewed-on: https://chromium-review.googlesource.com/990959
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#547559}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: e65dd61a5fea51751b5be4cdeede0aedc0eb34d6
diff --git a/tools/gn/bootstrap/bootstrap.py b/tools/gn/bootstrap/bootstrap.py
index 8096364..83f5838 100755
--- a/tools/gn/bootstrap/bootstrap.py
+++ b/tools/gn/bootstrap/bootstrap.py
@@ -192,7 +192,8 @@
           'ENABLE_LOCATION_SOURCE': 'false',
           'ENABLE_PROFILING': 'false',
           'CAN_UNWIND_WITH_FRAME_POINTERS': 'false',
-          'UNSAFE_DEVELOPER_BUILD': 'false'
+          'UNSAFE_DEVELOPER_BUILD': 'false',
+          'CAN_UNWIND_WITH_CFI_TABLE': 'false',
       })
 
   write_buildflag_header_manually(root_gen_dir,