Reland of git cl try: don't skip presubmit builders, but set dry_run property. (patchset #1 id:1 of https://codereview.chromium.org/1928373002/ )

Reason for revert:
Was me - too fast to pull the revert trigger. The CL in question has notry set to true :(

Original issue's description:
> Revert of git cl try: don't skip presubmit builders, but set dry_run property. (patchset #2 id:20001 of https://codereview.chromium.org/1926663002/ )
> 
> Reason for revert:
> Now only presubmit is scheduled on dry run, example CL:
> https://codereview.chromium.org/1804003002
> 
> Original issue's description:
> > Reland of git cl try: don't skip presubmit builders, but set dry_run property.
> > 
> > With a fix: actually set dry_run for presubmit, and don't set it for other builders.
> > 
> > R=machenbach@chromium.org,sergiyb@chromium.org
> > BUG=601128,594127,591030
> > 
> > Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=300295
> 
> TBR=sergiyb@chromium.org,tandrii@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=601128,594127,591030
> 
> Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=300337

TBR=sergiyb@chromium.org,tandrii@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=601128,594127,591030

Review-Url: https://codereview.chromium.org/1930363003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@300338 0039d316-1c4b-4281-b951-d872f2087c98