[Linux] Add field trial tuples to breakpad crash reports.

[Linux] Add field trial tuples to breakpad crash reports.

This is the Linux side of the following changes:
Windows: http://codereview.chromium.org/9432033
Mac: https://chromiumcodereview.appspot.com/10661057

Also cleans up some surrounding code:
  - Change strncpy() calls to safer base::strlcpy().
  - No need to NULL terminate after snprintf(), which does that already.
  - Use arraysize() throughout.
  - No need to call strlen() just to check if a string is empty.

BUG=145323
TEST=Linux crash reports show experiment chunks.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=154190

[Lei Zhang, 2012-08-28 23:10:22]

http://codereview.chromium.org/10890015/diff/1008/chrome/common/child_process...
File chrome/common/child_process_logging.h (right):

http://codereview.chromium.org/10890015/diff/1008/chrome/common/child_process...
chrome/common/child_process_logging.h:65: extern char g_num_variations[];
nit: move this up one line (alphabetical order) ditto in the .cc file

http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
File chrome/common/child_process_logging_posix.cc (right):

http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
chrome/common/child_process_logging_posix.cc:151:
std::min<size_t>(chunks.size(), kMaxReportedVariationChunks);
do you need the <size_t> part?

[Alexei Svitkine (slow), 2012-08-29 14:05:25]

http://codereview.chromium.org/10890015/diff/1008/chrome/common/child_process...
File chrome/common/child_process_logging.h (right):

http://codereview.chromium.org/10890015/diff/1008/chrome/common/child_process...
chrome/common/child_process_logging.h:65: extern char g_num_variations[];
On 2012/08/28 23:10:22, Lei Zhang wrote:
> nit: move this up one line (alphabetical order) ditto in the .cc file

Done.

http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
File chrome/common/child_process_logging_posix.cc (right):

http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
chrome/common/child_process_logging_posix.cc:151:
std::min<size_t>(chunks.size(), kMaxReportedVariationChunks);
On 2012/08/28 23:10:22, Lei Zhang wrote:
> do you need the <size_t> part?

Yes, because chunks.size() and kMaxReportedVariationChunks are different types 
(size_t equivalent and int).

[Lei Zhang, 2012-08-29 18:33:13]

http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
File chrome/common/child_process_logging_posix.cc (right):

http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
chrome/common/child_process_logging_posix.cc:151:
std::min<size_t>(chunks.size(), kMaxReportedVariationChunks);
On 2012/08/29 14:05:25, Alexei Svitkine wrote:
> On 2012/08/28 23:10:22, Lei Zhang wrote:
> > do you need the <size_t> part?
> 
> Yes, because chunks.size() and kMaxReportedVariationChunks are different types

> (size_t equivalent and int).

Shouldn't kMaxReportedVariationChunks be size_t?

[Alexei Svitkine (slow), 2012-08-29 18:41:25]

http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
File chrome/common/child_process_logging_posix.cc (right):

http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
chrome/common/child_process_logging_posix.cc:151:
std::min<size_t>(chunks.size(), kMaxReportedVariationChunks);
On 2012/08/29 18:33:13, Lei Zhang wrote:
> On 2012/08/29 14:05:25, Alexei Svitkine wrote:
> > On 2012/08/28 23:10:22, Lei Zhang wrote:
> > > do you need the <size_t> part?
> > 
> > Yes, because chunks.size() and kMaxReportedVariationChunks are different
types
> 
> > (size_t equivalent and int).
> 
> Shouldn't kMaxReportedVariationChunks be size_t?

My CL wasn't introducing that constant, so I wasn't going to change it
originally. However, you're right that it makes sense to change its type to
size_t.

Done now.

I've also updated kMaxReportedActiveExtensions similarly to be consistent.

[Lei Zhang, 2012-08-29 18:43:46]

On 2012/08/29 18:41:25, Alexei Svitkine wrote:
>
http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
> File chrome/common/child_process_logging_posix.cc (right):
> 
>
http://codereview.chromium.org/10890015/diff/2004/chrome/common/child_process...
> chrome/common/child_process_logging_posix.cc:151:
> std::min<size_t>(chunks.size(), kMaxReportedVariationChunks);
> On 2012/08/29 18:33:13, Lei Zhang wrote:
> > On 2012/08/29 14:05:25, Alexei Svitkine wrote:
> > > On 2012/08/28 23:10:22, Lei Zhang wrote:
> > > > do you need the <size_t> part?
> > > 
> > > Yes, because chunks.size() and kMaxReportedVariationChunks are different
> types
> > 
> > > (size_t equivalent and int).
> > 
> > Shouldn't kMaxReportedVariationChunks be size_t?
> 
> My CL wasn't introducing that constant, so I wasn't going to change it
> originally. However, you're right that it makes sense to change its type to
> size_t.
> 
> Done now.
> 
> I've also updated kMaxReportedActiveExtensions similarly to be consistent.

Thanks for doing the extra cleanup. I hope it doesn't bring up too many issues
on the trybots.

lgtm with green trybots.

[commit-bot: I haz the power, 2012-08-29 20:49:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/10890015/3008

[commit-bot: I haz the power, 2012-08-29 23:53:37]

Try job failure for 10890015-3008 (retry) on win_rel for step "browser_tests".
It's a second try, previously, step "browser_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2012-08-30 03:33:49]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/10890015/3008

[commit-bot: I haz the power, 2012-08-30 05:12:19]

Try job failure for 10890015-3008 (retry) on win for step "compile" (clobber
build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win&number...

[commit-bot: I haz the power, 2012-08-30 13:05:39]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/10890015/3008

[commit-bot: I haz the power, 2012-08-30 15:05:55]

Try job failure for 10890015-3008 (retry) on linux_rel for step
"interactive_ui_tests".
It's a second try, previously, step "interactive_ui_tests" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2012-08-30 15:11:30]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/asvitkine@chromium.org/10890015/3008

[commit-bot: I haz the power, 2012-08-30 17:37:15]

Change committed as 154190