new tab flashes white - follow up to 1876

[LaurenWags]

Description

Found while testing #1876

When opening a new tab, the tab flashes white before the background image is loaded. This happens whether you use light or dark theme for Brave.

Steps to Reproduce

1. Launch Brave.
2. Open a few new tabs. See white flash before tab image is loaded.
3. Switch between the new tabs. Sometimes you will see a white flash when switching between tabs.

Actual result:

Expected result:

No white flash.

Reproduces how often:

easily

Brave version (brave://version info)

Brave	0.60.28 Chromium: 72.0.3626.96 (Official Build) beta(64-bit)
Revision	84098ee7ef8622a9defc2ef043cd8930b617b10e-refs/branch-heads/3626@{#836}
OS	Mac OS X

Reproducible on current release: yes

• Does it reproduce on brave-browser dev/beta builds? yes

Website problems only:

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

Additional Information

Reproduced by @kjozwiak on macOS (Mojave)

[srirambv]

Issue reproduced on Linux as well

[btlechowski]

Reproduced on Windows

Brave	0.60.29 Chromium: 72.0.3626.96 (Official Build) beta (64-bit)
Revision	84098ee7ef8622a9defc2ef043cd8930b617b10e-refs/branch-heads/3626@{#836}
OS	Windows 7

[kjozwiak]

Looks like this landed in 0.61.x as per brave/brave-core#1695. Moved the issue into the 0.61.x milestone.

[rebron]

@rossmoody just a reminder, after you merge an uplift, in the issue set the milestone to where you merged it too, so 61.x in this case. Thanks for taking care of this one.

[rossmoody]

@rebron @kjozwiak thanks for fixing it up and the direction. appreciate it.

[GeetaSarvadnya]

The issue still persists on Linux 0.61.41. Tab flashes white from 4th tab onwards in below recording:

[btlechowski]

Verification passed on

Brave	0.61.45 Chromium: 73.0.3683.39 (Official Build) beta (64-bit)
Revision	cc53b0e12fcaf42e4bab8d6c23bd4fb7aae99f6c-refs/branch-heads/3683@{#413}
OS	Windows 7 Service Pack 1 Build 7601.24312

The white does not flash in Dark mode.

Still reproducible for Light mode. Logged #3575

Verification passed on

Brave	0.61.46 Chromium: 73.0.3683.39 (Official Build) beta (64-bit)
Revision	cc53b0e12fcaf42e4bab8d6c23bd4fb7aae99f6c-refs/branch-heads/3683@{#413}
OS	Linux mint

• The issue is reproducible in both White and Dark theme
• Added comments in New tab flashes white when in Light mode #3575 (comment)

Verification PASSED on macOS 10.14.3 x64 using the following build:

Brave	0.61.48 Chromium: 73.0.3683.56 (Official Build) beta(64-bit)
Revision	303af44e2f2948869279f120021c778855d76ead-refs/branch-heads/3683@{#653}
OS	Mac OS X

• Same results as the checks on Win/Linux.