dragging an existing tab on the tab bar will also drag a split view if the Split view is present before or after the tab

[GeetaSarvadnya]

Description

Found while testing #43213

dragging an existing tab on the tab bar will also drag a split view if the Split view is present before or after the tab

Steps to reproduce

1. Clean profile 1.77.54 CR134
2. Have several tabs open and also have a split view.
3. Make sure there are tabs before and after split view
4. Drag and drop a tab that is present before or after the splitview

Actual result

dragging an existing tab on the tab bar will also drag a split view if the Split view is present before or after the tab

Expected result

dragging an existing tab that is present before or after the split view should only drag and drop the tab not the split view

Reproduces how often

Easily reproduced

Brave version (brave://version info)

Brave	1.77.54 Chromium: 134.0.6998.15 (Official Build) nightly (64-bit)
Revision	b5eb0ad650247021f99f74cbe6a98cfe9cd02868
OS	Windows 10 Version 22H2 (Build 19045.5487)

Channel information

• release (stable)
• beta
• nightly

Reproducibility

• with Brave Shields disabled
• with Brave Rewards disabled
• in the latest version of Chrome

Miscellaneous information

cc: @brave/qa-team @rebron @simonhong @emerick

Thread for more details https://bravesoftware.slack.com/archives/CKNHM4RTK/p1740141588729229?thread_ts=1739912894.037299&cid=CKNHM4RTK

[GeetaSarvadnya]

Reproduced on

Brave | 1.76.68 Chromium: 134.0.6998.24 (Official Build) beta (arm64)
-- | --
Revision | eac610699a3bf7c2506522bc0603b1a97a6324a6
OS | macOS Version 15.3.1 (Build 24D70)