Revert of Add debug symbols to all generated .isolate. (patchset #1 id:420001 of...

Revert of Add debug symbols to all generated .isolate. (patchset #1 id:420001 of https://codereview.chromium.org/1245703002/ )

Reason for revert:
Speculative, possibly caused "dyld: Library not loaded: @rpath/libchrome_main_dll.dylib" test failures in http://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%29/builds/11859

Original issue's description:
> Add debug symbols to all generated .isolate.
>
> This will increase the amount of data being uploaded by a ~2x factor or so.
> Debug symbols are usually larger than the executable itself on pretty much all
> toolsets but generally have the advantage of being highly compressible. The
> increase of data not a problem anymore with isolate-go. There will be a small
> increase of latency but it should be bearable, especially by the gain of
> enabling stack traces to work for isolated tests on Swarming.
>
> R=jam@chromium.org
> BUG=98637
> CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
>
> Committed: https://crrev.com/8125ce3c695e6d8c02f3b51b16d49e17e7934bb4
> Cr-Commit-Position: refs/heads/master@{#349231}

TBR=jam@chromium.org,kbr@chromium.org,maruel@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=98637

Review URL: https://codereview.chromium.org/1354523002

Cr-Commit-Position: refs/heads/master@{#349342}