Tests are failing with errors like this:

AcceleratorsCocoaBrowserTest.MainMenuAcceleratorsInMapping (run #1):
[ RUN      ] AcceleratorsCocoaBrowserTest.MainMenuAcceleratorsInMapping
[1361:515:0615/193339:210535270587:FATAL:crashpad_client_mac.cc(411)] execvp /b/swarm_slave/work/isolated/isolated_runTnrdHD/out/Release/Chromium.app/Contents/Versions/53.0.2769.0/Chromium Framework.framework/Helpers/crashpad_handler: No such file or directory

First failed builds

https://build.chromium.org/p/chromium.mac/builders/Mac%20GN/builds/29603
https://build.chromium.org/p/chromium.mac/builders/Mac%20GN%20%28dbg%29/builds/34046

Suspecting:
  https://chromium.googlesource.com/chromium/src.git/+/0cc137a639e9eb687b0fbde47983d672bcc8ef9f

commit 0cc137a639e9eb687b0fbde47983d672bcc8ef9f
Author: rsesek <rsesek@chromium.org>
Date: Wed Jun 15 23:50:25 2016

[Mac/iOS/GN] Use rsync in copy_bundle_data instead of shutil.copytree.

As the TODO this fixes states, copytree preserves mtimes. This can cause
overbuild when building bundled products. Switch to using rsync to have more
control over copy parameters.

BUG= 297668 
R=dpranke@chromium.org

Review-Url: https://codereview.chromium.org/2075463002
Cr-Commit-Position: refs/heads/master@{#400047}

[modify] https://crrev.com/0cc137a639e9eb687b0fbde47983d672bcc8ef9f/build/toolchain/mac/copy_bundle_data.py