Fix location bar layout isn't triggered by page action icon change

[simonhong]

When page action icon is changed, location bar layout should be done.
This is regression of recent change of
BraveLocationBarView::ChildPreferredSizeChanged(). It should call
base class base method call.

Fixes brave/brave-browser#1561

I missed this when I reviewed #587.

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Windows
  • macOS
  • Linux
• Verified that these changes pass automated tests (npm test brave_unit_tests && npm test brave_browser_tests) on
  • Windows
  • macOS
  • Linux
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone

Test Plan:

1. Make omnibox unfocused
2. Click omnibox
3. Check findbar icon is overlapped or not

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

[bbondy]

Yep, always call base class when possible since even if it has nothing currently, it could in the future.

[bbondy]

tested and it works great btw.

[bbondy]

master: 6024245
0.56.x: 9b3e830
0.55.x: 01a712d