Sampling heap profiler: Force Full GC before retrieving the profile.

src/profiler/sampling-heap-profiler.h

Index: src/profiler/sampling-heap-profiler.h
diff --git a/src/profiler/sampling-heap-profiler.h b/src/profiler/sampling-heap-profiler.h
index 7b2386712d4ef14d37054687fa1ea380c2d22cdb..e0dc004d5576b7cca55593152d85e8a6a2fc4992 100644
--- a/src/profiler/sampling-heap-profiler.h
+++ b/src/profiler/sampling-heap-profiler.h
@@ -41,7 +41,7 @@ class AllocationProfile : public v8::AllocationProfile {
 class SamplingHeapProfiler {
  public:
   SamplingHeapProfiler(Heap* heap, StringsStorage* names, uint64_t rate,
-                       int stack_depth);
+                       int stack_depth, v8::HeapProfiler::SamplingFlags flags);
   ~SamplingHeapProfiler();
 
   v8::AllocationProfile* GetAllocationProfile();
@@ -130,6 +130,7 @@ class SamplingHeapProfiler {
   std::set<Sample*> samples_;
   const int stack_depth_;
   const uint64_t rate_;
+  v8::HeapProfiler::SamplingFlags flags_;
 
   friend class SamplingAllocationObserver;
 };