Reland "Update DevTools build output location in web_tests infrastruc…

…ture"

This reverts commit 9ddffef.

Reason for revert: The missing file for debug builds has been added in
https://crrev.com/c/2714551

Original change's description:
> Revert "Update DevTools build output location in web_tests infrastructure"
>
> This reverts commit 2941e09.
>
> Reason for revert: https://crbug.com/1180967
>
> Original change's description:
> > Update DevTools build output location in web_tests infrastructure
> >
> > The build output of DevTools will be removed from
> > `out/Default/resources/inspector` and instead the `gen/` directory will
> > be used. Therefore, we need to update the Blink web_tests infrastructure
> > to use the new location, which already works with the current version of
> > DevTools.
> >
> > I have confirmed locally that `npm run test` in the devtools-frontend
> > repository correctly picks up the new location and can run the tests.
> >
> > CC=​Rob.Paveza@microsoft.com
> > R=​dpranke@google.com
> >
> > Bug: 1174013
> > Change-Id: I37756b3cda7d9dfb2f61211016d0a1aad0d3100c
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2684274
> > Reviewed-by: Dirk Pranke <dpranke@google.com>
> > Auto-Submit: Tim van der Lippe <tvanderlippe@chromium.org>
> > Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#856244}
>
> Bug: 1174013
> Change-Id: I9649c811b1cd68aaef5fa9939fbd9a39c8845506
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2713518
> Auto-Submit: Austin Sullivan <asully@chromium.org>
> Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Cr-Commit-Position: refs/heads/master@{#856454}

Bug: 1174013
Change-Id: Ie760864689e15e86e5985bdfeb78748acf3fe05b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2714599
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Austin Sullivan <asully@chromium.org>
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
Cr-Commit-Position: refs/heads/master@{#858523}

third_party/blink/tools/blinkpy/web_tests/port/base.py

@@ -1332,7 +1332,8 @@ def perf_results_directory(self):
         return self.results_directory()
 
     def inspector_build_directory(self):
-        return self._build_path('resources', 'inspector')
+        return self._build_path('gen', 'third_party', 'devtools-frontend',
+                                'src', 'front_end')
 
     def generated_sources_directory(self):
         return self._build_path('gen')

third_party/blink/tools/blinkpy/web_tests/servers/apache_http_unittest.py

@@ -54,7 +54,8 @@ def fake_pid(_):
         output_dir = '/mock/output_dir'
         host.filesystem.maybe_make_directory(output_dir)
         host.filesystem.maybe_make_directory(
-            '/mock-checkout/out/Release/resources/inspector')
+            '/mock-checkout/out/Release/gen/third_party/devtools-frontend/src/front_end'
+        )
         host.filesystem.maybe_make_directory('/mock-checkout/out/Release/gen')
 
         server = ApacheHTTP(