Expose TickSample and its APIs in v8-profiler.h

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 7268eee4dce7d300a2c8ffcf8b7f40d176041076..2cda597298d8fcd3bfd5d178eeb9b30852b872d3 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -36,6 +36,7 @@
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/execution.h"
+#include "src/frames-inl.h"
 #include "src/gdb-jit.h"
 #include "src/global-handles.h"
 #include "src/icu_util.h"
@@ -7569,23 +7570,18 @@ bool Isolate::GetHeapCodeAndMetadataStatistics(
 
 void Isolate::GetStackSample(const RegisterState& state, void** frames,
                              size_t frames_limit, SampleInfo* sample_info) {
-  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
 #if defined(USE_SIMULATOR)
-  RegisterState regs;
-  regs.pc = state.pc;
-  regs.sp = state.sp;
-  regs.fp = state.fp;
-  if (!i::SimulatorHelper::FillRegisters(isolate, &regs)) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  if (!i::SimulatorHelper::FillRegisters(isolate,
+                                         const_cast<RegisterState*>(&state))) {

[alph, 2016/06/30 21:18:08]

please avoid using const_cast, as the caller is not expecting you to change the
state.
Bring back the regs variable.

[lpy, 2016/06/30 22:51:29]

Done.

     sample_info->frames_count = 0;
     sample_info->vm_state = OTHER;
     sample_info->external_callback_entry = nullptr;
     return;
   }
-#else
-  const RegisterState& regs = state;
 #endif
-  i::TickSample::GetStackSample(isolate, regs, i::TickSample::kSkipCEntryFrame,
-                                frames, frames_limit, sample_info);
+  TickSample::GetStackSample(this, state, TickSample::kSkipCEntryFrame, frames,
+                             frames_limit, sample_info);
 }
 
 size_t Isolate::NumberOfPhantomHandleResetsSinceLastCall() {