Avoid printing draw target info to stderr while running unit tests

Avoid printing draw target info to stderr while running unit tests

Change draw target dump function to return a SkString. Clients can do
whatever they want with the string.

BUG=skia:1837
Committed: http://code.google.com/p/skia/source/detail?r=12340

[Kimmo Kinnunen, 2013-11-14 06:17:05]

Would this work in use-cases GrDrawTargetCaps::print was used before?

(I would probably #ifdef SKDEBUG or remove the code altogether, but I don't know
the original use-cases..)

[caryclark, 2013-11-14 12:52:16]

This CL can be much more limited. It only needs to avoid using stdout/stderr
during test runs for now.

Once GrDebugf / SkDebugf can be redirected, it can test to see that the output
matches expectations.

https://codereview.chromium.org/72353003/diff/1/tests/GrDrawTargetTest.cpp
File tests/GrDrawTargetTest.cpp (right):

https://codereview.chromium.org/72353003/diff/1/tests/GrDrawTargetTest.cpp#ne...
tests/GrDrawTargetTest.cpp:20: SkASSERT(!result.isEmpty());
For now, the only change necessary is:

// Disabled until debug printing can be redirected during test runs
// (see bug 1836)
// caps->print();

[bsalomon, 2013-11-14 16:51:57]

On 2013/11/14 12:52:16, caryclark wrote:
> This CL can be much more limited. It only needs to avoid using stdout/stderr
> during test runs for now.
> 
> Once GrDebugf / SkDebugf can be redirected, it can test to see that the output
> matches expectations.

I think that might veer into testing-gone-wild territory. This function doesn't
get executed in normal builds ever (other than the unit test). It is turned on
by devs at compile time to see some useful stats about the GPU we're running on.
We could consider putting it behind the SK_DEVELOPER macro so that it isn't even
present in release builds (it predates that build option).

> 
> https://codereview.chromium.org/72353003/diff/1/tests/GrDrawTargetTest.cpp
> File tests/GrDrawTargetTest.cpp (right):
> 
>
https://codereview.chromium.org/72353003/diff/1/tests/GrDrawTargetTest.cpp#ne...
> tests/GrDrawTargetTest.cpp:20: SkASSERT(!result.isEmpty());
> For now, the only change necessary is:
> 
> // Disabled until debug printing can be redirected during test runs
> // (see bug 1836)
> // caps->print();

I see no problem with the change as it is now, though. It seems like dump() is a
generalization of the print() function that makes it potentially more useful.
Even if we did decide to test the output it's simple enough to SkDebugf the
returned string.

[bsalomon, 2013-11-21 14:49:39]

lgtm

[commit-bot: I haz the power, 2013-11-21 14:49:56]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/kkinnunen@nvidia.com/72353003/1

[commit-bot: I haz the power, 2013-11-21 15:23:17]

Change committed as 12340