Initialise raw pointer to null in FontBuilder constructor

Initialise raw pointer to null in FontBuilder constructor

RenderStyle* m_style on FontBuilder doesn't get initialised in the
constructor. The majority of methods on FontBuilder will attempt to deref
it as a garbage raw pointer if they get called before initForStyleResolve()
is called.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169447

[eseidel, 2014-03-18 05:47:38]

Test?  lgtm on the code change, but I'd really like to land a test, even if it
only crashes under asan.

[alancutter (OOO until 2018), 2014-03-18 06:19:05]

On 2014/03/18 05:47:38, eseidel wrote:
> Test?  lgtm on the code change, but I'd really like to land a test, even if it
> only crashes under asan.

I'm not sure how to write a test that passes on null deref crash but fails on
uninitialised read under ASAN.

To give context to this change we hit this scenario when animating fontSize via
element.animate() because StyleResolver::createKeyframeEffectModel() doesn't
initForStyleResolve(), this will be fixed in a separate patch shortly so a
LayoutTest isn't exactly suitable here. :)

[alancutter (OOO until 2018), 2014-03-18 06:42:18]

On 2014/03/18 06:19:05, alancutter wrote:
> On 2014/03/18 05:47:38, eseidel wrote:
> > Test?  lgtm on the code change, but I'd really like to land a test, even if
it
> > only crashes under asan.
> 
> I'm not sure how to write a test that passes on null deref crash but fails on
> uninitialised read under ASAN.
 
Scratch that, I wrote a unit test for this change, it's kind of a silly test
though...

[eseidel, 2014-03-18 07:04:25]

lgtm

[commit-bot: I haz the power, 2014-03-18 07:04:33]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/alancutter@chromium.org/197883021/20001

[commit-bot: I haz the power, 2014-03-18 07:05:52]

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

[commit-bot: I haz the power, 2014-03-18 07:05:52]

Try jobs failed on following builders:
  tryserver.blink on mac_blink_compile_dbg

[alancutter (OOO until 2018), 2014-03-18 12:28:21]

The CQ bit was checked by alancutter@chromium.org

[commit-bot: I haz the power, 2014-03-18 12:28:26]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/alancutter@chromium.org/197883021/20001

[commit-bot: I haz the power, 2014-03-18 14:04:08]

Change committed as 169447