Revert "Add console message in MixedContentChecker::HandleCertificateError"

This reverts commit dcfa99386d0b0f91107fdb8c248be833ba18fd25.

Reason for revert: Caused flaky tests: crbug.com/912431

Original change's description:
> Add console message in MixedContentChecker::HandleCertificateError
> 
> Print console message when subresources are loaded over broken HTTPS.
> Screenshot: https://drive.google.com/file/d/1Sn_2c162NmvCoIXFuFVB68z-MhzphcNT/view?usp=sharing
> 
> Bug: 587168
> Change-Id: I997a8da26f0fe015cc0103b96dcbaa7d40525eb8
> Reviewed-on: https://chromium-review.googlesource.com/c/1306779
> Commit-Queue: Livvie Lin <livvielin@chromium.org>
> Reviewed-by: Mustafa Emre Acer <meacer@chromium.org>
> Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
> Reviewed-by: Mike West <mkwst@chromium.org>
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Nate Chapin <japhet@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#614212}

TBR=sky@chromium.org,meacer@chromium.org,yhirano@chromium.org,japhet@chromium.org,mkwst@chromium.org,livvielin@chromium.org

Change-Id: I9142c895af7dd1c6a4c9ea7500ee0eca2ce9d118
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 587168, 912431
Reviewed-on: https://chromium-review.googlesource.com/c/1364974
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Commit-Queue: Rakina Zata Amni <rakina@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614290}
23 files changed