Revert of Debugger: preserve stepping state after evaluating breakpoint condition...

Revert of Debugger: preserve stepping state after evaluating breakpoint condition. (patchset #1 id:1 of https://codereview.chromium.org/1132643004/)

Reason for revert:
[Sheriff] This breaks TSAN (makes some tests marked as flaky permanently fail):
http://build.chromium.org/p/client.v8/builders/V8%20Linux64%20TSAN/builds/3882

Original issue's description:
> Debugger: preserve stepping state after evaluating breakpoint condition.
>
> R=ulan@chromium.org, yurys@chromium.org
> BUG=chromium:467180
> LOG=N

TBR=ulan@chromium.org,yurys@chromium.org,yangguo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:467180

Review URL: https://codereview.chromium.org/1130123007

Cr-Commit-Position: refs/heads/master@{#28436}