Add last resort to fallback chain in FontFallbackList::primaryFontData

Add last resort to fallback chain in FontFallbackList::primaryFontData

Change FontFallbackList::primaryFontData to fall back on the last
resort fallback font if fontDataAt returns NULL. This matches the
behavior of the getFontData method and ensures that a valid FontData
object is returned as expected by the primarySimpleFontData method.

BUG=344989
R=dglazkov@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=167862

[dglazkov, 2014-02-26 00:05:02]

lgtm...

no test?

[eae, 2014-02-26 00:09:26]

On 2014/02/26 00:05:02, Dimitri Glazkov wrote:
> lgtm...
> 
> no test?

The only call sites that seem to trigger this is through the PDF viewer and
testing the function itself in isolation isn't really practical with out lack of
unit testing helpers for the font code. When we clean up out font fallback
handling that is one of the many things I'd like to fix.

[dglazkov, 2014-02-26 00:16:37]

On 2014/02/26 00:09:26, eae wrote:
> On 2014/02/26 00:05:02, Dimitri Glazkov wrote:
> > lgtm...
> > 
> > no test?
> 
> The only call sites that seem to trigger this is through the PDF viewer and
> testing the function itself in isolation isn't really practical with out lack
of
> unit testing helpers for the font code. When we clean up out font fallback
> handling that is one of the many things I'd like to fix.

sgtm :)

[eae, 2014-02-26 02:10:41]

The CQ bit was checked by eae@chromium.org

[Paweł Hajdan Jr., 2014-02-26 04:40:37]

The CQ bit was unchecked by phajdan.jr@chromium.org

[commit-bot: I haz the power, 2014-02-26 04:40:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/eae@chromium.org/179983007/1

[Paweł Hajdan Jr., 2014-02-26 05:28:56]

The CQ bit was checked by phajdan.jr@chromium.org

[commit-bot: I haz the power, 2014-02-26 05:29:08]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/eae@chromium.org/179983007/1

[commit-bot: I haz the power, 2014-02-26 08:49:13]

Change committed as 167862