Fix DevTools CPU profiler after isolates merge.

Fix DevTools CPU profiler after isolates merge.

There was an obvious bug with missing call to SamplerRegistry::GetState.
I've also updated CpuProfiler to avoid stopping sampler, if it didn't started it.

R=vitalyr@chromium.org
BUG=none
TEST=none

Committed: http://code.google.com/p/v8/source/detail?r=7293

[mnaganov (inactive), 2011-03-21 16:17:34]

I think, CPUProfiler should have its own Sampler, but let's first introduce a
simple fix.

[Vitaly Repeshko, 2011-03-21 17:16:10]

LGTM, thanks!

http://codereview.chromium.org/6712062/diff/1/src/platform-linux.cc
File src/platform-linux.cc (right):

http://codereview.chromium.org/6712062/diff/1/src/platform-linux.cc#newcode953
src/platform-linux.cc:953: state = SamplerRegistry::GetState();
*Facepalm*

But please fix it in a slightly different way:
SamplerRegistry::State state;
while ((state = SamplerRegistry::GetState()) !=
SamplerRegistry::HAS_NO_SAMPLERS) { ... }

platform-macos.cc also needs to be fixed.

[mnaganov (inactive), 2011-03-21 17:37:36]

On 2011/03/21 17:16:10, Vitaly Repeshko wrote:
> LGTM, thanks!
> 
> http://codereview.chromium.org/6712062/diff/1/src/platform-linux.cc
> File src/platform-linux.cc (right):
> 
> http://codereview.chromium.org/6712062/diff/1/src/platform-linux.cc#newcode953
> src/platform-linux.cc:953: state = SamplerRegistry::GetState();
> *Facepalm*
> 
> But please fix it in a slightly different way:
> SamplerRegistry::State state;
> while ((state = SamplerRegistry::GetState()) !=
> SamplerRegistry::HAS_NO_SAMPLERS) { ... }
> 

Right. I missed 'continue' statements. Corrected.

> platform-macos.cc also needs to be fixed.