Add optional parameter to WTFReportBacktrace for stackframe count

Add optional parameter to WTFReportBacktrace for stackframe count

This patch gives epic yakshavers an optional parameter to control
how many stackframes to show when using WTFReportBacktrace. This
just exposes a previously static framesToShow value.

Users may find this useful in debugging deep traces.

This patch does not modify the BACKTRACE macro because macros
cannot have optional parameters.
This patch does not use templates this function is in a c block which
does not support templates ("templates must have C++ linkage").

TEST=manual

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=157400

[tony, 2013-09-04 16:51:47]

LGTM

[commit-bot: I haz the power, 2013-09-04 17:00:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pdr@chromium.org/23494018/1

[commit-bot: I haz the power, 2013-09-04 17:58:40]

Sorry for I got bad news for ya.
Compile failed with a clobber build on win_blink_rel.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2013-09-04 20:41:22]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pdr@chromium.org/23494018/4001

[commit-bot: I haz the power, 2013-09-04 21:23:05]

Sorry for I got bad news for ya.
Compile failed with a clobber build on win_blink_rel.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[pdr., 2013-09-06 00:10:19]

On 2013/09/04 21:23:05, I haz the power (commit-bot) wrote:
> Sorry for I got bad news for ya.
> Compile failed with a clobber build on win_blink_rel.
>
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...
> Your code is likely broken or HEAD is junk. Please ensure your
> code is not broken then alert the build sheriffs.
> Look at the try server FAQ for more details.

I've updated this to now work, and updated the change description appropriately.

This was a fun C++ learning exercise. Alloca is pretty obscure so this may not
be worth it to check in.

[esprehn, 2013-09-06 00:25:07]

On 2013/09/06 00:10:19, pdr wrote:
> On 2013/09/04 21:23:05, I haz the power (commit-bot) wrote:
> > Sorry for I got bad news for ya.
> > Compile failed with a clobber build on win_blink_rel.
> >
>
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...
> > Your code is likely broken or HEAD is junk. Please ensure your
> > code is not broken then alert the build sheriffs.
> > Look at the try server FAQ for more details.
> 
> I've updated this to now work, and updated the change description
appropriately.
> 
> This was a fun C++ learning exercise. Alloca is pretty obscure so this may not
> be worth it to check in.

I think it's fine to check in, you should just add a comment above it that says
something like "Use alloca to allocate on the stack since this function is used
in out of memory situations"

[commit-bot: I haz the power, 2013-09-06 21:56:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pdr@chromium.org/23494018/28001

[commit-bot: I haz the power, 2013-09-07 00:35:06]

Change committed as 157400