Roll DevTools Frontend from 1557a1c16778 to 60bf7bf3310f (2 revisions)

https://chromium.googlesource.com/devtools/devtools-frontend.git/+log/1557a1c16778..60bf7bf3310f

2020-06-08 patrick.brosset@microsoft.com DevTools: E2E test covering going from perf to sources
2020-06-08 kahinds@microsoft.com Fix Network request initiator tooltip

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/devtools-frontend-chromium
Please CC devtools-waterfall-sheriff-onduty@grotations.appspotmail.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:1069404,chromium:1079076
Tbr: devtools-waterfall-sheriff-onduty@grotations.appspotmail.com
Change-Id: I2a8ebbc4341d761e90145bd8cdf0725304397198
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2236375Reviewed-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@{#776199}

DEPS

@@ -253,7 +253,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling devtools-frontend
   # and whatever else without interference from each other.
-  'devtools_frontend_revision': '1557a1c1677842dc41629b15a994e793d2c56b89',
+  'devtools_frontend_revision': '60bf7bf3310fd88753cd275ea18860aa1644980b',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling libprotobuf-mutator
   # and whatever else without interference from each other.