Added an option to run bisect-builds.py from git checkout so that 'Downloading list of know…

Added an option (--use-local-repo) to run bisect-builds.py from git checkout so that 
'Downloading list of known revisions' step is faster. If the script is run with
--use-local-repo option, it will use "git svn find-rev <SHA1>" command to convert git hash 
to svn revision. This method is significantly faster than running the script
without git checkout.

Eg: Command to run:
time ./tools/bisect-builds.py -g 280588 -b 280590 --archive linux64 --use-local-repo

Output:
real	5m16.089s
user	3m50.326s
sys	1m1.190s

time ./tools/bisect-builds.py -g 280588 -b 280590 --archive linux64

Output:
real	10m51.194s
user	0m10.248s
sys	0m1.419s


BUG=390547
NOTRY=True

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=281936

[Robert Sesek, 2014-07-08 12:58:57]

I don't think this is a good switch name, given the upcoming transition to git.
This script is meant to be run without the requirement of a checkout, too. I'd
suggest --use-local-repo or something similar.

[pshenoy, 2014-07-08 16:48:04]

Please take a look.

[Robert Sesek, 2014-07-08 18:52:58]

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py
File tools/bisect-builds.py (right):

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:100: self.use_local_repo = use_local_repo
nit: blank line before and a comment about what this does.

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:295: command.append('svn')
Why .append() these things? command = ['svn', 'find-rev', git_sha1]

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:305: '--archive linux64 --git')
--use-local-repo

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:306: sys.exit(0)
Code 1 for errors

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:895: 'command.')
"from a Chromium checkout."

[pshenoy, 2014-07-08 19:58:19]

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py
File tools/bisect-builds.py (right):

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:100: self.use_local_repo = use_local_repo
On 2014/07/08 18:52:58, rsesek wrote:
> nit: blank line before and a comment about what this does.

Done.

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:295: command.append('svn')
On 2014/07/08 18:52:58, rsesek wrote:
> Why .append() these things? command = ['svn', 'find-rev', git_sha1]

Done.

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:305: '--archive linux64 --git')
On 2014/07/08 18:52:58, rsesek wrote:
> --use-local-repo

Done.

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:306: sys.exit(0)
On 2014/07/08 18:52:58, rsesek wrote:
> Code 1 for errors

Done.

https://codereview.chromium.org/378713002/diff/20001/tools/bisect-builds.py#n...
tools/bisect-builds.py:895: 'command.')
On 2014/07/08 18:52:58, rsesek wrote:
> "from a Chromium checkout."

Done.

[Robert Sesek, 2014-07-08 21:06:15]

LGTM

[pshenoy, 2014-07-08 21:23:02]

The CQ bit was checked by pshenoy@chromium.org

[commit-bot: I haz the power, 2014-07-08 21:25:59]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/pshenoy@chromium.org/378713002/40001

[commit-bot: I haz the power, 2014-07-09 04:45:54]

Change committed as 281936