Add generic V8 API functions for controlling profiling aspects.

Add generic V8 API functions for controlling profiling aspects.

As we'll have several aspects of heap profiling, it is more handy to control them using binary flags than by individual functions. CPU profiling represent just a particular aspect to control, so {Pause,Resume}Profiler and IsProfilerPaused are only left for compatibility.

For now, PROFILER_FLAG_HEAP_STATS and PROFILER_FLAG_JS_CONSTRUCTOR are equivalent, but later will be split.

Review URL: http://codereview.chromium.org/159581

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2574 ce2b1a6d-e550-0410-aec6-3dcde31c8c00