Build fix after r170811

This CL Just adds #ifdef to V8RecursionScope::m_isolate to fix mac builds.

TBR=esprehn@chromium.org

Review URL: https://codereview.chromium.org/225083002

git-svn-id: svn://svn.chromium.org/blink/trunk@170813 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert 170813 "Build fix after r170811"

r170813 didn't fix build issues caused by r170811.
I'll revert both r170811 and r170813.

> Build fix after r170811
> 
> This CL Just adds #ifdef to V8RecursionScope::m_isolate to fix mac builds.
> 
> TBR=esprehn@chromium.org
> 
> Review URL: https://codereview.chromium.org/225083002

TBR=haraken@chromium.org

Review URL: https://codereview.chromium.org/225133002

git-svn-id: svn://svn.chromium.org/blink/trunk@170814 bbb929c8-8fbe-4397-9dbb-9b2b20218538