Removed RuntimeProfilerRateLimiter class and RuntimeProfiler::IsSomeIsolateInJS.

Removed RuntimeProfilerRateLimiter class and RuntimeProfiler::IsSomeIsolateInJS.

Removing the former was basically a consequence of removing the latter. The net
effect is, apart from less code, that the signal sender thread is much more
explicit about its logic now.

Committed: http://code.google.com/p/v8/source/detail?r=13212

[Michael Starzinger, 2012-12-12 15:21:29]

LGTM.