[cr135 follow up] Regression of download indicator for insecure downloads.

[mkarolin]

Description:
Prior to cr135 when a user attempts an insecure download we changed the download icon to an exclamation point icon. See #29376 for the original issue.

In cr135 upstream switched from using the custom download button machinery to using the download button in the toolbar pinning container and so our customization for insecure downloads was lost.

STR:

1. Install Brave with cr135
2. Launch Brave
3. Navigate to https://www.thinkbroadband.com/download
4. Right-click on http://ipv4.download.thinkbroadband.com:8080/1GB.zip
5. Chose Save Link As...
6. Click Save
7. Observe the download button in the toolbar

Actual result:

In inactive state regular download button icon is shown

Expected result:
In inactive state exclamation point icon is shown

[kjozwiak]

The above requires 1.77.96 or higher for 1.77.x verification 👍 Created #45269 so that's a known issue re: improving the UI.

[LaurenWags]

Verified with

Brave | 1.77.96 Chromium: 135.0.7049.52 (Official Build) (x86_64)
-- | --
Revision | fb998e48b1fb293cd93b86a89c56d68efef03046
OS | macOS Version 14.7.4 (Build 23H420)

Reproduced the issue using 1.77.95 Chromium: 135.0.7049.52:

Using 1.77.96 Chromium: 135.0.7049.52,

• ensured that a yellow ! icon appears when attempting to download an insecure file using the STR/Cases outlined via [cr135 follow up] Regression of download indicator for insecure downloads. #45159 (comment).

• ensured that the ! icon appears when there's multiple downloads (one download that's secure and one that's insecure)
• ensured that the ! icon goes from yellow -> grey when inactive

• ensured that clicking on Keep downloads the file and removes the ! icon (restores the default download icon)

• ensured that Download insecure file works without any issues/failures

• ensured that Delete from history removes the insecure download from the download panel and brave://downloads