Fix infinite loop caused by ElideText()

Fix infinite loop caused by ElideText()

BUG=238405
R=ben@chromium.org, mmoss@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=198545

[Dmitry Titov, 2013-04-19 22:12:40]

Michael, I think you have added the code to check for pango returning 0 width
sometimes. Unfortunately, there is a missing check for empty line, where the
empty string does produce the 0 width, and the ElideText() returns an empty
string fragment, which causes the code calling it go into infinite loop.

It's a bit hard to get a repro (without applying a patch I have locally)... It
happens when avaliable width is less then a single character.

[Michael Moss, 2013-04-19 22:24:42]

lgtm

[commit-bot: I haz the power, 2013-04-19 23:08:34]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dimich@chromium.org/13846005/1

[commit-bot: I haz the power, 2013-04-19 23:08:37]

Presubmit check for 13846005-1 failed and returned exit status 1.

INFO:root:Found 1 file(s).

Running presubmit commit checks ...
Running /b/commit-queue/workdir/chromium/PRESUBMIT.py

** Presubmit Messages **
If this change has an associated bug, add BUG=[bug number].

** Presubmit ERRORS **
Missing LGTM from an OWNER for these files:
    ui/base/text/text_elider.cc

[Dmitry Titov, 2013-04-22 20:01:45]

Ben, could you please do the OWNERS look?

[Dmitry Titov, 2013-04-24 19:58:30]

ping? Thanks!

[Ben Goodger (Google), 2013-04-25 17:16:52]

seems like you could write a unit test for this.

[Dmitry Titov, 2013-04-26 02:52:02]

Thanks Ben, of course I should have written a test :-)

Working on a test, I've realized that the fix is not right.
The ElideText() should return empty string if there is not enough space for even
minimal content. Instead, the WrapWord() which is wrapping the word in the case
when available width is less then the width of the word, should consume at least
one character per line and not go into infinite loop.

Added a test for ElideText with ELIDE_END flag and Label test. Label test will
go into infinite loop w/o the fix.

Michael and Ben, I think I need another look from both of you now.

[Michael Moss, 2013-04-26 15:24:50]

lgtm

[Dmitry Titov, 2013-04-29 21:34:47]

Ben - PTAL? Got a test, and a better fix.

[Ben Goodger (Google), 2013-04-30 19:21:56]

lgtm

[commit-bot: I haz the power, 2013-04-30 19:57:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dimich@chromium.org/13846005/11001

[commit-bot: I haz the power, 2013-04-30 22:28:23]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dimich@chromium.org/13846005/31001

[commit-bot: I haz the power, 2013-05-01 01:13:57]

Retried try job too often on win7_aura for step(s) interactive_ui_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win7_aura&...

[commit-bot: I haz the power, 2013-05-06 18:58:02]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dimich@chromium.org/13846005/31001

[commit-bot: I haz the power, 2013-05-06 21:00:57]

Retried try job too often on mac_rel for step(s) interactive_ui_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=mac_rel&nu...

[Dmitry Titov, 2013-05-06 21:43:12]

Committed patchset #3 manually as r198545.