Fix SVGImageChromeClient::scheduleAnimation() crash.

Fix SVGImageChromeClient::scheduleAnimation() crash.

|SVGImageChromeClient::scheduleAnimation()| can be called without valid |m_image| since r168612.
The CL adds null check before proceeding.

TESTS=svg/as-image/*.html
BUG=350907

[haraken, 2014-03-10 06:23:19]

LGTM

> TESTS=svg/as-image/*.html

Was the tests crashing? Otherwise you want to add a new test that covers the
change in this CL.

[kouhei (in TOK), 2014-03-10 06:24:20]

On 2014/03/10 06:23:19, haraken wrote:
> LGTM
> 
> > TESTS=svg/as-image/*.html
> 
> Was the tests crashing? Otherwise you want to add a new test that covers the
> change in this CL.

Yes, they were crashing locally (w/ enable_oilpan), but this is hard to repro
consistently as it depends on gc timing.

[kouhei (in TOK), 2014-03-10 06:24:52]

The CQ bit was checked by kouhei@chromium.org

[commit-bot: I haz the power, 2014-03-10 06:24:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kouhei@chromium.org/191913004/1

[commit-bot: I haz the power, 2014-03-10 07:02:04]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-10 07:02:04]

Try jobs failed on following builders: win_blink_rel

[fs, 2014-03-10 09:28:06]

Thanks for fixing!

[jochen (gone - plz use gerrit), 2014-03-10 14:56:11]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-03-10 14:56:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kouhei@chromium.org/191913004/1

[commit-bot: I haz the power, 2014-03-10 15:36:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kouhei@chromium.org/191913004/1

[commit-bot: I haz the power, 2014-03-10 16:26:12]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-10 16:26:12]

Try jobs failed on following builders: win_blink_rel

[jochen (gone - plz use gerrit), 2014-03-10 16:32:03]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-03-10 16:40:46]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kouhei@chromium.org/191913004/1

[commit-bot: I haz the power, 2014-03-10 16:55:13]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-10 16:55:14]

Failed to apply the patch.

[jochen (gone - plz use gerrit), 2014-03-10 21:12:04]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-03-10 21:12:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kouhei@chromium.org/191913004/1

[eseidel, 2014-03-10 21:26:30]

How do we test this?

[eseidel, 2014-03-10 21:27:10]

This can't be oilpan only, since Karen says she has reports of this from the
wild.  When I search the crash db, I only see 8 reports total though. :(

[commit-bot: I haz the power, 2014-03-10 22:04:31]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-10 22:04:32]

Commit queue rejected this change because the description was changed
between the time the change entered the commit queue and the time it
was ready to commit. You can safely check the commit box again.

[eseidel, 2014-03-10 22:05:47]

Landed this in https://codereview.chromium.org/193323003.  I don't like the
patch w/o a test, but karen believes this is blocking her ability to roll
dev-channel so taking the pragmatic approach to give folks more connected to
this issue time to sort out the right approach.

[kouhei (in TOK), 2014-03-11 01:27:31]

On 2014/03/10 22:05:47, eseidel wrote:
> Landed this in https://codereview.chromium.org/193323003.  I don't like the
> patch w/o a test, but karen believes this is blocking her ability to roll
> dev-channel so taking the pragmatic approach to give folks more connected to
> this issue time to sort out the right approach.

Actually this does crash in non-oilpan builds on TESTS=svg/as-image/*.html .
However I couldn't find a way to consistently repro this.