Updated MallocHooks to collect stack traces when memory is allocated.

runtime/vm/profiler.h

Index: runtime/vm/profiler.h
diff --git a/runtime/vm/profiler.h b/runtime/vm/profiler.h
index ee87a31d954051b61af6a7a822b7f2bb78da23eb..ffe98da290131830dc0dca97e7f7b1b5539c8e19 100644
--- a/runtime/vm/profiler.h
+++ b/runtime/vm/profiler.h
@@ -58,6 +58,7 @@ class Profiler : public AllStatic {
   static void DumpStackTrace();
 
   static void SampleAllocation(Thread* thread, intptr_t cid);
+  static Sample* NativeSampleAllocation();

[Cutch, 2017/02/08 00:28:54]

SampleNativeAllocation

[bkonyi, 2017/02/08 01:37:05]

Done.

 
   // SampleThread is called from inside the signal handler and hence it is very
   // critical that the implementation of SampleThread does not do any of the
@@ -268,6 +269,15 @@ class Sample {
     state_ = ClassAllocationSampleBit::update(allocation_sample, state_);
   }
 
+  bool is_native_allocation_sample() const {
+    return NativeAllocationSampleBit::decode(state_);
+  }
+
+  void set_is_native_allocation_sample(bool native_allocation_sample) {
+    state_ =
+        NativeAllocationSampleBit::update(native_allocation_sample, state_);
+  }
+
   Thread::TaskKind thread_task() const { return ThreadTaskBit::decode(state_); }
 
   void set_thread_task(Thread::TaskKind task) {
@@ -331,7 +341,8 @@ class Sample {
     kClassAllocationSampleBit = 6,
     kContinuationSampleBit = 7,
     kThreadTaskBit = 8,  // 5 bits.
-    kNextFreeBit = 13,
+    kNativeAllocationSampleBit = 13,
+    kNextFreeBit = 14,
   };
   class HeadSampleBit : public BitField<uword, bool, kHeadSampleBit, 1> {};
   class LeafFrameIsDart : public BitField<uword, bool, kLeafFrameIsDartBit, 1> {
@@ -344,6 +355,8 @@ class Sample {
       : public BitField<uword, bool, kTruncatedTraceBit, 1> {};
   class ClassAllocationSampleBit
       : public BitField<uword, bool, kClassAllocationSampleBit, 1> {};
+  class NativeAllocationSampleBit
+      : public BitField<uword, bool, kNativeAllocationSampleBit, 1> {};
   class ContinuationSampleBit
       : public BitField<uword, bool, kContinuationSampleBit, 1> {};
   class ThreadTaskBit