Clamp, not cast length value in CSS length conversion

Clamp, not cast length value in CSS length conversion

computeLength() in CSSPrimitiveValue was returning only static_cast'ed,
but not clamped values, leading to float overflows in font and Skia code
down the line.

The test result needs to be compared visually as the crash does not trigger
using dumpAsText().

BUG=610645
TEST=fast/text/letter-spacing-crash.html

Review-Url: https://codereview.chromium.org/1987223002
Cr-Commit-Position: refs/heads/master@{#394390}
(cherry picked from commit 6dd652af9ab5089938ce8c24513b4a768d0c5b45)

Committed: https://chromium.googlesource.com/chromium/src/+/f48d7f9108d7718324e9c9e5cd7008a8862dc12c

[drott, 2016-05-20 07:21:37]

Description was changed from

==========
Clamp, not cast length value in CSS length conversion

computeLength() in CSSPrimitiveValue was returning only static_cast'ed,
but not clamped values, leading to float overflows in font and Skia code
down the line.

The test result needs to be compared visually as the crash does not trigger
using dumpAsText().

BUG=610645
TEST=fast/text/letter-spacing-crash.html

Review-Url: https://codereview.chromium.org/1987223002
Cr-Commit-Position: refs/heads/master@{#394390}
(cherry picked from commit 6dd652af9ab5089938ce8c24513b4a768d0c5b45)
==========

to

==========
Clamp, not cast length value in CSS length conversion

computeLength() in CSSPrimitiveValue was returning only static_cast'ed,
but not clamped values, leading to float overflows in font and Skia code
down the line.

The test result needs to be compared visually as the crash does not trigger
using dumpAsText().

BUG=610645
TEST=fast/text/letter-spacing-crash.html

Review-Url: https://codereview.chromium.org/1987223002
Cr-Commit-Position: refs/heads/master@{#394390}
(cherry picked from commit 6dd652af9ab5089938ce8c24513b4a768d0c5b45)

Committed:
https://chromium.googlesource.com/chromium/src/+/f48d7f9108d7718324e9c9e5cd70...
==========

[drott, 2016-05-20 07:21:39]

Committed patchset #1 (id:1) manually as
f48d7f9108d7718324e9c9e5cd7008a8862dc12c.