[Android] Add ring_buffer option to adb.Logcat

[Android] Add ring_buffer option to adb.Logcat

We can use this option, e.g., to request only the "crash" portion of a
logcat.

BUG=

Committed: https://crrev.com/d642544d7ac9987fb728c0251ae2587ec3b07bc5
Cr-Commit-Position: refs/heads/master@{#321324}

[perezju, 2015-03-18 16:49:50]

perezju@chromium.org changed reviewers:
+ jbudorick@chromium.org

[perezju, 2015-03-18 16:49:51]

This one should be a should be a simple one. Adds support for the logcat -b
option.

[jbudorick, 2015-03-18 16:53:01]

lgtm w/ optional nit

https://codereview.chromium.org/1017163002/diff/1/build/android/pylib/device/...
File build/android/pylib/device/adb_wrapper.py (right):

https://codereview.chromium.org/1017163002/diff/1/build/android/pylib/device/...
build/android/pylib/device/adb_wrapper.py:335: if ring_buffer:
optional nit: could do

  for buffer_name in ring_buffer or []:
    cmd.extend(['-b', buffer_name])

[perezju, 2015-03-19 09:00:45]

On 2015/03/18 16:53:01, jbudorick wrote:
> lgtm w/ optional nit
> 
>
https://codereview.chromium.org/1017163002/diff/1/build/android/pylib/device/...
> File build/android/pylib/device/adb_wrapper.py (right):
> 
>
https://codereview.chromium.org/1017163002/diff/1/build/android/pylib/device/...
> build/android/pylib/device/adb_wrapper.py:335: if ring_buffer:
> optional nit: could do
> 
>   for buffer_name in ring_buffer or []:
>     cmd.extend(['-b', buffer_name])

I guess I'll pass on that optional nit. I don't like how it would look like. :-P

[perezju, 2015-03-19 09:00:48]

The CQ bit was checked by perezju@chromium.org

[commit-bot: I haz the power, 2015-03-19 09:00:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1017163002/1

[commit-bot: I haz the power, 2015-03-19 10:06:39]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-19 10:07:15]

Patchset 1 (id:??) landed as
https://crrev.com/d642544d7ac9987fb728c0251ae2587ec3b07bc5
Cr-Commit-Position: refs/heads/master@{#321324}