Update DevTools DEPS.
Update DevTools DEPS.

Rolling third_party/depot_tools: https://chromium.googlesource.com/chromium/tools/depot_tools/+log/6a5aa66..bdd8936

TBR=machenbach@chromium.org,liviurau@chromium.org

Change-Id: I202fb1ae31956a005ea077a5302881daca164d4b
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2015930
Reviewed-by: Devtools Autoroller <075cca983f8f93eec1be8cf9702f03e09507e730@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Devtools Autoroller <075cca983f8f93eec1be8cf9702f03e09507e730@chops-service-accounts.iam.gserviceaccount.com>

ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend