fix(tab): return ScrollContentWidth

[seraph17]

No description provided.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed (or fixed any issues), please reply here (e.g. I signed it!) and we'll verify it.

---

What to do if you already signed the CLA

Individual signers

• It's possible we don't have your GitHub username or you're using a different email address on your commit. Check your existing CLA data and verify that your email is set on your git commits.

Corporate signers

• Your company has a Point of Contact who decides which employees are authorized to participate. Ask your POC to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the Google project maintainer to go/cla#troubleshoot (Public version).
• The email used to register you as an authorized contributor must be the email used for the Git commit. Check your existing CLA data and verify that your email is set on your git commits.
• The email used to register you as an authorized contributor must also be attached to your GitHub account.

[seraph17]

I signed it!

[googlebot]

CLAs look good, thanks!

[codecov-io]

Codecov Report

Merging #633 into rc0.10.0 will decrease coverage by 0.07%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##           rc0.10.0     #633      +/-   ##
============================================
- Coverage      94.9%   94.83%   -0.08%     
============================================
  Files            68       67       -1     
  Lines          2847     2768      -79     
  Branches        428      414      -14     
============================================
- Hits           2702     2625      -77     
  Misses           50       50              
+ Partials         95       93       -2

Impacted Files	Coverage Δ
packages/tab-bar/index.tsx	85.71% <100%> (ø)	⬆️
packages/chips/Chip.tsx	97.77% <0%> (-0.21%)	⬇️
packages/chips/ChipSet.tsx	98.64% <0%> (-0.12%)	⬇️
packages/text-field/Input.tsx	96.72% <0%> (ø)	⬆️
packages/snackbar/index.tsx

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update a376474...c68df5d. Read the comment docs.

[moog16]

@seraph17 - Wow can't believe our unit tests didn't catch this.

I just checked the tests and it is lacking. Could you add one? This is a probably causing issues, so I'd rather get this in than not. I can create an issue if you don't have the bandwidth.

[moog16]

#672 tests passing and signed cla in #633 (comment).

Opened issue #671 as TODO for a test.

Merging