Harden a security CHECK in Font::individualCharacterRanges

Harden a security CHECK in Font::individualCharacterRanges

This patch switches to a check (crash) for an assertion failure in
Font::individualCharacterRanges which is only known to occur on OSX
10.9.5. A comment has been added to explain this further. This has the
side benefit of exposing other cases of this bug on other platforms that
may be a more serious issue.

BUG=620952
Review-Url: https://codereview.chromium.org/2110703002
Cr-Commit-Position: refs/heads/master@{#402912}
(cherry picked from commit e4ff7ba1cfab002517238841505ca9bb7aff6595)

Committed: https://chromium.googlesource.com/chromium/src/+/da8f89d0a31c471924f02479b126a7e0bb709205

[pdr., 2016-07-14 22:45:16]

Description was changed from

==========
Harden a security CHECK in Font::individualCharacterRanges

This patch switches to a check (crash) for an assertion failure in
Font::individualCharacterRanges which is only known to occur on OSX
10.9.5. A comment has been added to explain this further. This has the
side benefit of exposing other cases of this bug on other platforms that
may be a more serious issue.

BUG=620952

Review-Url: https://codereview.chromium.org/2110703002
Cr-Commit-Position: refs/heads/master@{#402912}
(cherry picked from commit e4ff7ba1cfab002517238841505ca9bb7aff6595)
==========

to

==========
Harden a security CHECK in Font::individualCharacterRanges

This patch switches to a check (crash) for an assertion failure in
Font::individualCharacterRanges which is only known to occur on OSX
10.9.5. A comment has been added to explain this further. This has the
side benefit of exposing other cases of this bug on other platforms that
may be a more serious issue.

BUG=620952

Review-Url: https://codereview.chromium.org/2110703002
Cr-Commit-Position: refs/heads/master@{#402912}
(cherry picked from commit e4ff7ba1cfab002517238841505ca9bb7aff6595)

Committed:
https://chromium.googlesource.com/chromium/src/+/da8f89d0a31c471924f02479b126...
==========

[pdr., 2016-07-14 22:45:18]

Committed patchset #1 (id:1) manually as
da8f89d0a31c471924f02479b126a7e0bb709205.