Fix renderer crash from adblock page(removed stats from adblock webui) (uplift to 1.21.x)

[brave-builds]

Uplift of #7811
fix brave/brave-browser#13775

Approved, please ensure that before merging:

• You have checked CI and the builds, lint, and tests all pass or are not related to your PR.
• You have tested your change on Nightly.
• The PR milestones match the branch they are landing to.

After you merge:

• The associated issue milestone is set to the smallest version that the changes is landed on.

[kjozwiak]

Restarting macOS as the node failed to `Check out from version control as per https://ci.brave.com/job/brave-core-build-pr-macos/job/PR-7836/1/execution/node/13/log/.

[2021-02-04T23:16:07.401Z] Checking out Revision bb0d4f36d14ee97048bf9f01afac194698b3abed (PR-7836)
[2021-02-04T23:16:07.401Z]  > git config core.sparsecheckout # timeout=10
[2021-02-04T23:16:07.482Z]  > git checkout -f bb0d4f36d14ee97048bf9f01afac194698b3abed # timeout=10
Could not checkout bb0d4f36d14ee97048bf9f01afac194698b3abed

[kjozwiak]

test-browser failed on Win x64 due to AdBlockServiceTest.CosmeticFilteringProtect1p failing as per https://ci.brave.com/job/pr-brave-browser-pr7811_fix_renderer_crash_from_adblock_page_1.21.x-windows/1/execution/node/234/log/. However, this is a known issue and will be resolved via #7777.

20:23:54  1 test failed:
20:23:54      AdBlockServiceTest.CosmeticFilteringProtect1p (../../brave/browser/brave_shields/ad_block_service_browsertest.cc:922)

[kjozwiak]

Uplift into 1.21.x approved after deliberating with @brave/uplift-approvers. QA has verified the PR on Nightly as per #7811 (comment).