Fix plot script.

Fix plot script.

The script for the time line plot has been broken since r15484, which
changed the format of tick entries in v8.log.

To prevent this from happening in the future, I added a test case.

R=hpayer@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=15581

[Yang, 2013-07-09 09:39:24]

On 2013/07/09 09:36:39, Yang wrote:

Review guidance:

- I changed tools/profviz/composer.js to reflect the changes in r15484.
- test/mjsunit/tools/profviz.js mocks the usage of the plot script as used in
tools/profviz/worker.js
- test/mjsunit/tools/profviz-test.log is a sample log
- test/mjsunit/tools/profviz-test.default is the expected output as JSON array.

[Hannes Payer (out of office), 2013-07-10 07:31:50]

https://codereview.chromium.org/18826008/diff/1/test/mjsunit/tools/profviz.js
File test/mjsunit/tools/profviz.js (right):

https://codereview.chromium.org/18826008/diff/1/test/mjsunit/tools/profviz.js...
test/mjsunit/tools/profviz.js:78: if (create_baseline) {
looks like create_baseline is always false? or is there some js voodoo going on
:-)

[Hannes Payer (out of office), 2013-07-10 07:37:24]

One more comment...

https://codereview.chromium.org/18826008/diff/1/test/mjsunit/tools/profviz.js
File test/mjsunit/tools/profviz.js (right):

https://codereview.chromium.org/18826008/diff/1/test/mjsunit/tools/profviz.js...
test/mjsunit/tools/profviz.js:74: output("# objects: " + objects);
would it make sense to assert on expected values for start, end, and objects?

[Hannes Payer (out of office), 2013-07-10 07:47:25]

LGTM

[Yang, 2013-07-10 07:53:35]

Committed patchset #1 manually as r15581 (presubmit successful).