Update DevTools DEPS (trusted)

Rolling third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/7784911..c2a6159

Roll created at https://cr-buildbucket.appspot.com/build/8709641934838512465

Bug: none
Change-Id: If7ce37c65548ca81b0da981e870ffae32f487fb8
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6725500
Bot-Commit: Devtools Autoroller <devtools-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Devtools Autoroller <devtools-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>

Author: devtools-ci-autoroll-builder

DEPS

@@ -18,7 +18,7 @@ vars = {
   'buildtools_revision': '17bdad4a57ed807c4bef2a1947248d5fefef4efe',
 
   'depot_tools_url': 'https://chromium.googlesource.com/chromium/tools/depot_tools.git',
-  'depot_tools_revision': '7784911e43aef4eba901c491ea3a04ac0106d54f',
+  'depot_tools_revision': 'c2a6159a0d39caa1686977317d6f1c8891d2c83e',
 
   'inspector_protocol_url': 'https://chromium.googlesource.com/deps/inspector_protocol',
   'inspector_protocol_revision': '6d1ae0f13aae6ad381ca31b17b88a0f5af29ca94',