Most webui buttons are hidden in new dark theme with c74

[jasonrsadler]

Description

When in main settings in dark mode, regular (not 'action') buttons (e.g. the 'cancel' button within modal, the 'default browser' button, etc) cannot be seen.

Test plan / Steps to Reproduce

1. Open Brave
2. Open settings (switch to dark theme if not already)
3. Go to 'Clear Browsing Data'

Actual result:

'cancel' button is hidden

Expected result:

'cancel' button should be easily seen

Reproduces how often:

easily

Brave version (brave://version info)

0.64.x (c74)

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds? No

Website problems only:

• Does the issue resolve itself when disabling Brave Shields?
• Is the issue reproducible on the latest version of Chrome?

Additional Information

cc @petemill

[rebron]

@petemill Can you take a look?

[petemill]

Yes I’ll fix it when c74 lands again

[petemill]

This also affects normal buttons, changing title / description to reflect that

[bsclifton]

Resolved when C74 was merged to master with #3931 😄

[LaurenWags]

Verified passed with

Brave	0.64.72 Chromium: 74.0.3729.131 (Official Build) beta(64-bit)
Revision	518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f-refs/branch-heads/3729@{#954}
OS	Mac OS X

• Verified test plan from description for both dark and light themes. cc @kjozwiak to check macOS using Mojave for 'matches macOS theme' option.
  
  

Verification PASSED on macOS 10.14.4 x64 using the following build:

Brave	0.64.72 Chromium: 74.0.3729.131 (Official Build) beta(64-bit)
Revision	518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f-refs/branch-heads/3729@{#954}
OS	Mac OS X

• Went through the test case outlined under Most webui buttons are hidden in new dark theme with c74 #3894 (comment)
• Ensured that the Cancel button was visible when switching between Light/Dark when using Same as MacOS
• Ensured that the Cancel button was visible when using both the native Light/Dark theme within Brave

Verification passed on

Brave	0.64.72 Chromium: 74.0.3729.131 (Official Build) beta (64-bit)
Revision	518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f-refs/branch-heads/3729@{#954}
OS	Windows 10 OS Build 17134.523

• Verified the STR mentioned in the description
• Verified that the Cancel button is seen when browser theme is changed to Dark
• Verified that the Cancel button is seen when OS theme is changed to Dark
• Verified that buttons are shown clearly when theme is switched from Dark to Light and vice versa

Verification passed on

Brave	0.64.72 Chromium: 74.0.3729.131 (Official Build) beta(64-bit)
Revision	518a41c1fa7ce1c8bb5e22346e82e42b4d76a96f-refs/branch-heads/3729@{#954}
OS	Ubuntu 18.04 LTS

This issue is blocked on Linux, because of #965