[profiler] Implement POC Sampling Heap Profiler

src/profiler/heap-profiler.h

 // Copyright 2009-2010 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PROFILER_HEAP_PROFILER_H_
 #define V8_PROFILER_HEAP_PROFILER_H_
 
 #include "src/base/smart-pointers.h"
 #include "src/isolate.h"
 #include "src/list.h"
 
 namespace v8 {
 namespace internal {
 
 // Forward declarations.
 class AllocationTracker;
 class HeapObjectsMap;
 class HeapSnapshot;
+class SamplingHeapProfiler;
 class StringsStorage;
 
 class HeapProfiler {
  public:
   explicit HeapProfiler(Heap* heap);
   ~HeapProfiler();
 
   size_t GetMemorySizeUsedByProfiler();
 
   HeapSnapshot* TakeSnapshot(
       v8::ActivityControl* control,
       v8::HeapProfiler::ObjectNameResolver* resolver);
 
+  bool StartSamplingHeapProfiler(uint64_t sample_interval, int stack_depth);
+  void StopSamplingHeapProfiler();
+  AllocationProfile* GetAllocationProfile();
+
   void StartHeapObjectsTracking(bool track_allocations);
   void StopHeapObjectsTracking();
   AllocationTracker* allocation_tracker() const {
     return allocation_tracker_.get();
   }
   HeapObjectsMap* heap_object_map() const { return ids_.get(); }
   StringsStorage* names() const { return names_.get(); }
 
   SnapshotObjectId PushHeapObjectsStats(OutputStream* stream,
                                         int64_t* timestamp_us);
@@ skipping 30 matching lines @@
   Heap* heap() const;
 
   // Mapping from HeapObject addresses to objects' uids.
   base::SmartPointer<HeapObjectsMap> ids_;
   List<HeapSnapshot*> snapshots_;
   base::SmartPointer<StringsStorage> names_;
   List<v8::HeapProfiler::WrapperInfoCallback> wrapper_callbacks_;
   base::SmartPointer<AllocationTracker> allocation_tracker_;
   bool is_tracking_object_moves_;
   base::Mutex profiler_mutex_;
+  base::SmartPointer<SamplingHeapProfiler> sampling_heap_profiler_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PROFILER_HEAP_PROFILER_H_