[Sheriff] Revert "Add tests to verify page load metrics are recorded in cases of crashes."

This reverts commit 4cf270351c08ec51555b4a3f215a7199aac5289e.

Reason for revert: UkmIsRecordedForCrashedTabPage fails at Linux ASan LSan Tests:  https://ci.chromium.org/ui/p/chromium/builders/ci/Linux%20ASan%20LSan%20Tests%20(1)/108558/overview

Original change's description:
> Add tests to verify page load metrics are recorded in cases of crashes.
>
> Browser tests are added to verify page load metrics are recorded in
> cases of crashes. Crashes are simulated by navigating to chrome debug
> urls and by shutting down render process.
> During all these crashes, the destructor of the PageLoadTracker is
> called and page load metrics are hence recorded.
>
> Bug: 1383971
> Change-Id: Ia909820cf3237974e888471028a9fe8119b92720
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4027239
> Commit-Queue: Hao Liu <haoliuk@chromium.org>
> Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1075581}

Bug: 1383971
Change-Id: Ia2c2356031207f95280b0fcd732f1be26c649d7c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4055268
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Roman Sorokin <rsorokin@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Roman Sorokin <rsorokin@google.com>
Cr-Commit-Position: refs/heads/main@{#1075733}