Roll Depot Tools from b655a28e1097 to 9949ab7a4b1c (3 revisions)

https://chromium.googlesource.com/chromium/tools/depot_tools.git/+log/b655a28e1097..9949ab7a4b1c

2020-07-20 saagarsanghavi@google.com Preliminary changes to git cl and presubmit_support
2020-07-20 ehmaldonado@google.com bot_update: Refactor branch to detach and checkout.
2020-07-20 cwallez@chromium.org gclient: deprecated use_relative_hooks

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/depot-tools-chromium-autoroll
Please CC sokcevic@google.com,ajp@google.com,apolito@google.com,ehmaldonado@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/master/autoroll/README.md

Bug: chromium:1104182,chromium:1107325
Tbr: sokcevic@google.com,ajp@google.com,apolito@google.com,ehmaldonado@google.com
Change-Id: Ib9176861c2f0465216f9c0abe504752c1b5c6764
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2308869Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#790177}

DEPS

@@ -895,7 +895,7 @@ deps = {
   },
 
   'src/third_party/depot_tools':
-    Var('chromium_git') + '/chromium/tools/depot_tools.git' + '@' + 'b655a28e1097f393ba8f0519b43abb92bc38f69e',
+    Var('chromium_git') + '/chromium/tools/depot_tools.git' + '@' + '9949ab7a4b1cb3c342b38129b4e0bfcfb2ef5749',
 
   'src/third_party/devtools-frontend/src':
     Var('chromium_git') + '/devtools/devtools-frontend' + '@' + Var('devtools_frontend_revision'),