Fix SizeLabelToMinWidth() function such that no unnecessary space between warning label and Discard…

Fix SizeLabelToMinWidth() function such that no unnecessary space between warning label and Discard button on download shelf.

Note, this bug has been there for more than 3 years. The string
change in crrev.com/2443343002 exposed this issue. The reason this bug
was only reproducible on Win is because Win's font is narrower than
other OSs' (a.k.a label with the same text on Win yields a smaller width)

BUG=668472
Review-Url: https://codereview.chromium.org/2556573002
Cr-Commit-Position: refs/heads/master@{#437563}
(cherry picked from commit 047611df69b7f337f96d4ce684d21cb69baeb0b8)

Committed: https://chromium.googlesource.com/chromium/src/+/fdc8672287946320d9547ddbc9bc29d721e30459

[Jialiu Lin, 2016-12-10 19:03:16]

Description was changed from

==========
Fix SizeLabelToMinWidth() function such that no unnecessary space between
warning label and Discard button on download shelf.

Note, this bug has been there for more than 3 years. The string
change in crrev.com/2443343002 exposed this issue. The reason this bug
was only reproducible on Win is because Win's font is narrower than
other OSs' (a.k.a label with the same text on Win yields a smaller width)

BUG=668472

Review-Url: https://codereview.chromium.org/2556573002
Cr-Commit-Position: refs/heads/master@{#437563}
(cherry picked from commit 047611df69b7f337f96d4ce684d21cb69baeb0b8)
==========

to

==========
Fix SizeLabelToMinWidth() function such that no unnecessary space between
warning label and Discard button on download shelf.

Note, this bug has been there for more than 3 years. The string
change in crrev.com/2443343002 exposed this issue. The reason this bug
was only reproducible on Win is because Win's font is narrower than
other OSs' (a.k.a label with the same text on Win yields a smaller width)

BUG=668472

Review-Url: https://codereview.chromium.org/2556573002
Cr-Commit-Position: refs/heads/master@{#437563}
(cherry picked from commit 047611df69b7f337f96d4ce684d21cb69baeb0b8)

Committed:
https://chromium.googlesource.com/chromium/src/+/fdc8672287946320d9547ddbc9bc...
==========

[Jialiu Lin, 2016-12-10 19:03:18]

Committed patchset #1 (id:1) manually as
fdc8672287946320d9547ddbc9bc29d721e30459.