Revert of Add support for escaped target names in isolate driver. (patchset #6 id...

Revert of Add support for escaped target names in isolate driver. (patchset #6 id:100001 of https://codereview.chromium.org/970203003/)

Reason for revert:
Likely broke Mac 10.9 dbg: http://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%29/builds/3709

Original issue's description:
> Add support for escaped target names in isolate driver.
>
> Currently the isolate_driver.py which creates the dependency files
> used by the isolate system, does a simple split on all spaces when
> trying to identify targets.
>
> This can fail if the target name contains a space in the name. In
> ninja, spaces are escaped with a $-prefix. An example would be
> 'Content$ Shell$ Helper.app'.
>
> This CL adds support for such target names and ensures that they
> stay as one item.
>
> BUG=462248
>
> Committed: https://crrev.com/8fb598c1b7b9a6b944e2ec15e989e80cdf7522c0
> Cr-Commit-Position: refs/heads/master@{#319356}

TBR=avi@chromium.org,maruel@chromium.org,falken@chromium.org,vadimsh@chromium.org,nyquist@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=462248

Review URL: https://codereview.chromium.org/985753002

Cr-Commit-Position: refs/heads/master@{#319448}