[cleanup] Remove unnecessary legacy definition
[cleanup] Remove unnecessary legacy definition

Change-Id: I4ac4aec8a190be9beadf4a116d1863cb73734230
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2270544
Commit-Queue: Sigurd Schneider <f04d242e109628a27a0f75fd49a87722bcf291fd@chromium.org>
Commit-Queue: Tim van der Lippe <dba8716ee7f8d16236046f74d2167cb94410f6ed@chromium.org>
Auto-Submit: Sigurd Schneider <f04d242e109628a27a0f75fd49a87722bcf291fd@chromium.org>
Reviewed-by: Tim van der Lippe <dba8716ee7f8d16236046f74d2167cb94410f6ed@chromium.org>

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