Get rid of Isolate::safe_stack_iterator_counter

Get rid of Isolate::safe_stack_iterator_counter

This change removes per-isolate counter of active SafeStackFrameIterators. The counter is used by stack frames implementations to avoid accessing pointers to heap objects when traversing stack for CPU profiler (so called "safe" mode). Each StackFrame instance is owned by single iterator and has a pointer to it so we can simply mark the iterator as "safe" or not and read the field in the stack frames instead of going into the isolate.

BUG=None
R=loislo@chromium.org, svenpanne@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=15317

[loislo, 2013-06-25 09:36:26]

lgtm

https://codereview.chromium.org/17585008/diff/4001/src/frames.h
File src/frames.h (right):

https://codereview.chromium.org/17585008/diff/4001/src/frames.h#newcode819
src/frames.h:819: const bool is_safe_iterator_;
I'd call it 'can_use_heap_objects_'

[yurys, 2013-06-25 09:44:17]

https://codereview.chromium.org/17585008/diff/4001/src/frames.h
File src/frames.h (right):

https://codereview.chromium.org/17585008/diff/4001/src/frames.h#newcode819
src/frames.h:819: const bool is_safe_iterator_;
On 2013/06/25 09:36:26, loislo wrote:
> I'd call it 'can_use_heap_objects_'

Done. Thank you.

[Sven Panne, 2013-06-25 10:00:25]

lgtm

[yurys, 2013-06-25 10:09:28]

Committed patchset #5 manually as r15317 (presubmit successful).