Fix various stray bugs in the GN auto-roller, and repair the DEPS file.

Fix various stray bugs in the GN auto-roller, and repair the DEPS file.

The GN auto-roller script had two bugs in it, one of which was
damaging the DEPS file: when we updated the buildtools revision,
we would drop a newline and end up concatenating the following line.
A second roll would then drop that concatenated line, shrinking the
file, and so one. This was bad.

Secondly, the auto-roller would leave buildtools/ checked out on a
branch that had been merged into origin/master; this might cause
merge conflicts and confusion down the road.

R=thakis@chromium.org
BUG=

Committed: https://crrev.com/7a694fe11fb4602ddd56edfa34a1b48f26049f63
Cr-Commit-Position: refs/heads/master@{#343804}

[Dirk Pranke, 2015-08-17 21:36:15]

Patchset #1 (id:1) has been deleted

[Nico, 2015-08-17 21:38:15]

lgtm

no test?

https://codereview.chromium.org/1289233003/diff/20001/tools/gn/bin/roll_gn.py
File tools/gn/bin/roll_gn.py (right):

https://codereview.chromium.org/1289233003/diff/20001/tools/gn/bin/roll_gn.py...
tools/gn/bin/roll_gn.py:352: # Intentionally leave the src checkout on the new
branch w/ the roll
s:w/:with

[Dirk Pranke, 2015-08-17 21:43:27]

On 2015/08/17 21:38:15, Nico wrote:
> lgtm
> 
> no test?
> 

No, testing this script would be awkward at best (hard to see if it would do
anything other than be
an empty series of mocks) and isn't worth it for the number of times we use this
script and
the manual controls built into it (worst case we commit bad revisions to
buildtools that would
have to be reverted or skipped over).

> https://codereview.chromium.org/1289233003/diff/20001/tools/gn/bin/roll_gn.py
> File tools/gn/bin/roll_gn.py (right):
> 
>
https://codereview.chromium.org/1289233003/diff/20001/tools/gn/bin/roll_gn.py...
> tools/gn/bin/roll_gn.py:352: # Intentionally leave the src checkout on the new
> branch w/ the roll
> s:w/:with

done.

[Dirk Pranke, 2015-08-17 21:44:59]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2015-08-17 21:45:00]

The patchset sent to the CQ was uploaded after l-g-t-m from thakis@chromium.org
Link to the patchset: https://codereview.chromium.org/1289233003/#ps40001
(title: "update w/ review feedback")

[commit-bot: I haz the power, 2015-08-17 21:45:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1289233003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1289233003/40001

[commit-bot: I haz the power, 2015-08-18 00:31:03]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-18 00:31:03]

Try jobs failed on following builders:
  linux_chromium_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Nico, 2015-08-18 00:37:13]

On 2015/08/17 21:43:27, Dirk Pranke wrote:
> On 2015/08/17 21:38:15, Nico wrote:
> > lgtm
> > 
> > no test?
> > 
> 
> No, testing this script would be awkward at best (hard to see if it would do
> anything other than be
> an empty series of mocks) and isn't worth it for the number of times we use
this
> script and
> the manual controls built into it (worst case we commit bad revisions to
> buildtools that would
> have to be reverted or skipped over).

One technique for situations like this is to have tests for small stand-aline
functions (the thing that was missing the newline could be such a function)
inline and just run them every time the script runs:
https://code.google.com/p/chromium/codesearch#chromium/src/tools/linux/dump-s...

[Dirk Pranke, 2015-08-18 01:32:10]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2015-08-18 01:34:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1289233003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1289233003/40001

[commit-bot: I haz the power, 2015-08-18 05:11:36]

Committed patchset #2 (id:40001)

[commit-bot: I haz the power, 2015-08-18 05:12:17]

Patchset 2 (id:??) landed as
https://crrev.com/7a694fe11fb4602ddd56edfa34a1b48f26049f63
Cr-Commit-Position: refs/heads/master@{#343804}