Revert of chromium_tests: raise infra failure when no compile targets are specified (patchset #1 id:

Revert of chromium_tests: raise infra failure when no compile targets are specified (patchset #1 id:1 of https://codereview.chromium.org/1376453002/ )

Reason for revert:
This is not a valid assumption, e.g. the clang bots all use the empty compile target as build target and were all broken with this. (As discussed previously, even!)

Original issue's description:
> chromium_tests: raise infra failure when no compile targets are specified
> 
> This relies on default compile targets either on the recipe side or ninja,
> but breaks badly with e.g. analyze. We're trying to make as much of bot
> config explicit as possible.
> 
> BUG=536186
> 
> Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=296903

TBR=tandrii@chromium.org,sergiyb@chromium.org,hans@chromium.org,phajdan.jr@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=536186
Review URL: https://codereview.chromium.org/1377453003/
TBR=phajdan

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=296916

[Nico, 2015-09-28 18:55:08]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2015-09-28 18:55:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1372133003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1372133003/20001

[commit-bot: I haz the power, 2015-09-28 18:56:01]

Committed patchset #2 (id:20001) as
http://src.chromium.org/viewvc/chrome?view=rev&revision=296916