This reverts commit 5fd1defb.

Reason for revert: breaks v8 because hook names are optional

Original change's description:
> gclient runhooks: now with less spammy progress notifications
> 
> Bug: 772741
> Change-Id: I62ad64219ba27ee4ea26ceb603b1133dff4a2e04
> Reviewed-on: https://chromium-review.googlesource.com/727194
> Reviewed-by: Nico Weber <thakis@chromium.org>
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Commit-Queue: Daniel Cheng <dcheng@chromium.org>

TBR=dcheng@chromium.org,thakis@chromium.org,dpranke@chromium.org

Change-Id: I7dee0ca188f5ca34232f16e6496249fc9f49fa96
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 772741
Reviewed-on: https://chromium-review.googlesource.com/728959Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Daniel Cheng <dcheng@chromium.org>