Delete dead code related to the removed helper apps.

Delete dead code related to the removed helper apps.

It is no longer clear if we will be adding more helper variants in the
near future. This change removes any additional dead code related to the
helper apps.

BUG=520680
Committed: https://crrev.com/0c619649467faa44c72db1ddfabbf59e535b4d31
Cr-Commit-Position: refs/heads/master@{#349970}

[Greg K, 2015-09-17 23:26:00]

kerrnel@chromium.org changed reviewers:
+ mark@chromium.org

[Greg K, 2015-09-17 23:26:40]

Mark, would you please review?

[Mark Mentovai, 2015-09-17 23:48:29]

LGTM

https://codereview.chromium.org/1354703002/diff/20001/chrome/browser/memory_d...
File chrome/browser/memory_details_mac.cc (right):

https://codereview.chromium.org/1354703002/diff/20001/chrome/browser/memory_d...
chrome/browser/memory_details_mac.cc:213: // Get PIDs of the helper.
The comment was correct before, “helpers,” because many helper processes appear,
even if they all come from the same executable.

https://codereview.chromium.org/1354703002/diff/20001/chrome/browser/memory_d...
chrome/browser/memory_details_mac.cc:216: NULL);
Use nullptr in new code.

[Greg K, 2015-09-18 16:59:06]

kerrnel@chromium.org changed reviewers:
+ derat@chromium.org, thestig@chromium.org

[Greg K, 2015-09-18 16:59:07]

derat@chromium.org: Please review changes in 
app_shell.gyp

thestig@chromium.org: Please review changes in 
chrome/browser/memory_details_mac.cc
chrome/chrome.gyp
chrome/common/chrome_constants.h
chrome/common/chrome_constants.cc
chrome/test/base/chrome_process_util.cc

And anything else you see fit. 

Thanks,

Greg

[Daniel Erat, 2015-09-18 17:01:19]

rubber-stamp lgtm for extensions/ if it still builds (i don't have any history
with the lines that are being deleted)

[Lei Zhang, 2015-09-18 17:36:13]

lgtm

[Greg K, 2015-09-21 17:35:46]

The CQ bit was checked by kerrnel@chromium.org

[commit-bot: I haz the power, 2015-09-21 17:37:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1354703002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1354703002/20001

[commit-bot: I haz the power, 2015-09-21 18:40:04]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-21 18:40:35]

Patchset 2 (id:??) landed as
https://crrev.com/0c619649467faa44c72db1ddfabbf59e535b4d31
Cr-Commit-Position: refs/heads/master@{#349970}