Rename iterator debugging flag in GN.

Rename iterator debugging flag in GN.

Convert from "disable"=true to "enable"=false for clarity.

Add hints to GN build for debugging.

Removed the !is_android check in the iterator debugging. This is redundant with the is_linux check (is_linux used to be set for Android which is why this code got written).

Committed: https://crrev.com/e134d6c0f0f778251e38615bda7b241f077c5455
Cr-Commit-Position: refs/heads/master@{#341608}

[brettw, 2015-08-03 20:06:42]

brettw@chromium.org changed reviewers:
+ dpranke@chromium.org

[brettw, 2015-08-03 20:06:42]

I was using this flag to debug on Windows and the double-negative was making it
difficult for me to grok.

[brettw, 2015-08-03 20:06:49]

The CQ bit was checked by brettw@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-03 20:07:03]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1256783007/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1256783007/1

[commit-bot: I haz the power, 2015-08-03 20:09:12]

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

[commit-bot: I haz the power, 2015-08-03 20:09:13]

Dry run: Try jobs failed on following builders:
  linux_chromium_compile_dbg_32_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  ios_dbg_simulator_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_dbg_simulator...)
  ios_rel_device_ninja on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
  mac_chromium_compile_dbg_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)
  win8_chromium_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_ng/...)

[Dirk Pranke, 2015-08-03 20:12:20]

lgtm

[brettw, 2015-08-03 20:38:22]

The CQ bit was checked by brettw@chromium.org

[brettw, 2015-08-03 20:38:22]

The patchset sent to the CQ was uploaded after l-g-t-m from dpranke@chromium.org
Link to the patchset: https://codereview.chromium.org/1256783007/#ps20001
(title: "merge")

[commit-bot: I haz the power, 2015-08-03 20:38:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1256783007/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1256783007/20001

[commit-bot: I haz the power, 2015-08-03 21:06:21]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-08-03 21:06:54]

Patchset 2 (id:??) landed as
https://crrev.com/e134d6c0f0f778251e38615bda7b241f077c5455
Cr-Commit-Position: refs/heads/master@{#341608}