Add a self-test for gm, similar to our self-test for skdiff.

Add a self-test for gm, similar to our self-test for skdiff.
Committed: https://code.google.com/p/skia/source/detail?r=6380

[rmistry, 2012-11-12 12:51:07]

LGTM

https://codereview.appspot.com/6827068/diff/1/gm/tests/run.sh
File gm/tests/run.sh (right):

https://codereview.appspot.com/6827068/diff/1/gm/tests/run.sh#newcode4
gm/tests/run.sh:4: # TODO: for now, assumes that it is being run from .../trunk
Should be easy to add a check that verifies that it is run from PWD=trunk and
fails with a msg if it does not.

https://codereview.appspot.com/6827068/diff/1/gm/tests/run.sh#newcode4
gm/tests/run.sh:4: # TODO: for now, assumes that it is being run from .../trunk
TODO -> TODO(epoger) ?

https://codereview.appspot.com/6827068/diff/1/gm/tests/run.sh#newcode8
gm/tests/run.sh:8: 
Might be useful verify that two arguments are provided and fail with a helpful
msg if they are not.

[epoger, 2012-11-12 18:05:16]

https://codereview.appspot.com/6827068/diff/1/gm/tests/run.sh
File gm/tests/run.sh (right):

https://codereview.appspot.com/6827068/diff/1/gm/tests/run.sh#newcode4
gm/tests/run.sh:4: # TODO: for now, assumes that it is being run from .../trunk
On 2012/11/12 12:51:07, rmistry wrote:
> Should be easy to add a check that verifies that it is run from PWD=trunk and
> fails with a msg if it does not.

Better yet... I made it cd into the proper directory automatically.

I added a similar change to tools/tests/run.sh, and added that to this same CL. 
Thanks for the nudge.

https://codereview.appspot.com/6827068/diff/1/gm/tests/run.sh#newcode8
gm/tests/run.sh:8: 
On 2012/11/12 12:51:07, rmistry wrote:
> Might be useful verify that two arguments are provided and fail with a helpful
> msg if they are not.

Good idea. Done throughout here and tools/tests/run.sh.

[rmistry, 2012-11-12 18:45:38]

LGTM