Revert of Fix some build symbol configuration.

Revert of Fix some build symbol configuration. (patchset #2 id:20001 of https://codereview.chromium.org/1182663007/)

Reason for revert:
Broke Linux clobber:

https://build.chromium.org/p/chromium.linux/builders/Linux%20GN%20Clobber/builds/1307/steps/compile/logs/stdio

Original issue's description:
> Fix some build symbol configuration.
>
> Remove -gdwarf-4 from GYP build. This is the default for GCC 4.8 which is now required, so this command-line argument is redundant.
>
> Only set use_debug_fission in the GN build in debug mode. This matches GYP. Release mode symbols will be non-fission.
>
> Implement linux_symbols target in GN. Convert dump_app_syms from sh to Python for better GN usability, and it's more readable for normal programmers on the team.
>
> Reland of https://codereview.chromium.org/1179393004/
>
> TBR=thakis@chromium.org
>
> Committed: https://crrev.com/07d847b1c5451748f16f4e7973ce8ef9078d47a2
> Cr-Commit-Position: refs/heads/master@{#334690}

TBR=thakis@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/22d6e38d5efdb6a71df80a37094d4b97d7bc060f
Cr-Commit-Position: refs/heads/master@{#334744}

[brettw, 2015-06-16 23:28:45]

Created Revert of Fix some build symbol configuration.

[commit-bot: I haz the power, 2015-06-16 23:29:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1187233002/1

[commit-bot: I haz the power, 2015-06-16 23:31:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-16 23:32:01]

Patchset 1 (id:??) landed as
https://crrev.com/22d6e38d5efdb6a71df80a37094d4b97d7bc060f
Cr-Commit-Position: refs/heads/master@{#334744}