Expose TickSample and its APIs in v8-profiler.h

include/v8-profiler.h

Index: include/v8-profiler.h
diff --git a/include/v8-profiler.h b/include/v8-profiler.h
index b2c1dc9818ac8e4f78660e48d6a0992815495fb5..6a09d50ea5635da3f1eff41aa995095b4d59592a 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -46,6 +46,40 @@ template class V8_EXPORT std::vector<v8::CpuProfileDeoptInfo>;
 
 namespace v8 {
 
+// TickSample captures the information collected for each sample.
+struct TickSample {
+  // Internal profiling (with --prof + tools/$OS-tick-processor) wants to
+  // include the runtime function we're calling. Externally exposed tick
+  // samples don't care.
+  enum RecordCEntryFrame { kIncludeCEntryFrame, kSkipCEntryFrame };
+
+  TickSample()
+      : state(OTHER),
+        pc(nullptr),
+        external_callback_entry(nullptr),
+        frames_count(0),
+        has_external_callback(false),
+        update_stats(true) {}
+  void Init(Isolate* isolate, const v8::RegisterState& state,
+            RecordCEntryFrame record_c_entry_frame, bool update_stats);
+  static bool GetStackSample(Isolate* isolate, const v8::RegisterState& state,
+                             RecordCEntryFrame record_c_entry_frame,
+                             void** frames, size_t frames_limit,
+                             v8::SampleInfo* sample_info);
+  StateTag state;  // The state of the VM.
+  void* pc;        // Instruction pointer.
+  union {
+    void* tos;  // Top stack value (*sp).
+    void* external_callback_entry;
+  };
+  static const unsigned kMaxFramesCountLog2 = 8;
+  static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
+  void* stack[kMaxFramesCount];                 // Call stack.
+  unsigned frames_count : kMaxFramesCountLog2;  // Number of captured frames.
+  bool has_external_callback : 1;
+  bool update_stats : 1;  // Whether the sample should update aggregated stats.
+};
+
 /**
  * CpuProfileNode represents a node in a call graph.
  */