Update bookmarks toolbar folder icons

[bsclifton]

• Windows icons are back to yellow
• macOS and Linux use a gray colored icon (Linux has slightly different dimensions)

Having a proper icon solves the visibility issue for sub-folders on private window.

Fixes brave/brave-browser#17463
Fixes brave/brave-browser#17214

Test plan (needs to be ran on macOS, Windows, and Linux)

1. New profile
2. Hamburger menu => Bookmarks => Show bookmarks
3. Add a few folders to the bookmarks toolbar
4. Add a few subfolders (to cover test plan in Follow up of #16940 - Brave branded bookmarks subfolder images are not shown clearly in Private tabs brave-browser#17214)
5. Verify images look like below (see each OS screenshot) in Regular window
6. Opening a new Private window should look like dark mode
7. Sub-folders in bookmarks toolbar in private mode should be like light mode

Windows

macOS

Linux

Submitter Checklist:

• I confirm that no security/privacy review is needed, or that I have requested one
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally: npm run test -- brave_browser_tests, npm run test -- brave_unit_tests, npm run lint, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

[bsclifton]

Ready for review! 😄 @simonhong @mariospr would you all be able to help me get a screenshot for Linux / macOS? (light mode, dark mode). You can edit the top post and share there

[karenkliu]

Windows looks as expected! 🚀

[mkarolin]

LGTM

[simonhong]

++ - attached screenshots from macOS and linux

[kjozwiak]

Test Case 1 - brave/brave-browser#17463

Verification PASSED on Win 10 x64 using the following build:

Brave | 1.31.35 Chromium: 93.0.4577.63 (Official Build) nightly (64-bit)
-- | --
Revision | ff5c0da2ec0adeaed5550e6c7e98417dac77d98a-refs/branch-heads/4577@{#1135}
OS | Windows 10 OS Version 2009 (Build 19042.1165)

Ensured that the bookmark icons are matching the ones via #10037 (comment) when upgrading and installing a new profile. Examples:

Upgrade Case

Example	Example

Clean Install

Example	Example

---

Verification PASSED on PopOS 21.04 x64 using the following build:

Brave | 1.31.35 Chromium: 93.0.4577.63 (Official Build) nightly (64-bit)
--- | ---
Revision | ff5c0da2ec0adeaed5550e6c7e98417dac77d98a-refs/branch-heads/4577@{#1135}
OS | Linux

Ensured that the bookmark icons are matching the ones via #10037 (comment) when upgrading and installing a new profile. Examples:

Upgrade Case

Example	Example

Clean Install

Example	Example

---

Verification PASSED on macOS 11.5.2 x64 using the following build:

Brave | 1.31.35 Chromium: 93.0.4577.63 (Official Build) nightly (x86_64)
--- | ---
Revision | ff5c0da2ec0adeaed5550e6c7e98417dac77d98a-refs/branch-heads/4577@{#1135}
OS | macOS Version 11.5.2 (Build 20G95)

Ensured that the bookmark icons are matching the ones via #10037 (comment) when upgrading and installing a new profile. Examples:

Upgrade Case

Example	Example

Clean Install

Example	Example

Test Case 2 - brave/brave-browser#17214

Verification PASSED on Win 10 x64 using the following build:

Brave | 1.31.35 Chromium: 93.0.4577.63 (Official Build) nightly (64-bit)
-- | --
Revision | ff5c0da2ec0adeaed5550e6c7e98417dac77d98a-refs/branch-heads/4577@{#1135}
OS | Windows 10 OS Version 2009 (Build 19042.1165)

Private Window	Tor Window