Allocate the profiler sample buffer and zone segments with virtual memory instead of malloc.

runtime/vm/profiler.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_PROFILER_H_
 #define RUNTIME_VM_PROFILER_H_
 
 #include "vm/allocation.h"
 #include "vm/bitfield.h"
 #include "vm/code_observers.h"
@@ skipping 503 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(CodeLookupTable);
 };
 
 
 // Ring buffer of Samples that is (usually) shared by many isolates.
 class SampleBuffer {
  public:
   static const intptr_t kDefaultBufferCapacity = 120000;  // 2 minutes @ 1000hz.
 
   explicit SampleBuffer(intptr_t capacity = kDefaultBufferCapacity);
-
-  ~SampleBuffer() {
-    if (samples_ != NULL) {
-      free(samples_);
-      samples_ = NULL;
-      cursor_ = 0;
-      capacity_ = 0;
-    }
-  }
+  ~SampleBuffer();
 
   intptr_t capacity() const { return capacity_; }
 
   Sample* At(intptr_t idx) const;
   intptr_t ReserveSampleSlot();
   Sample* ReserveSample();
   Sample* ReserveSampleAndLink(Sample* previous);
 
   void VisitSamples(SampleVisitor* visitor) {
     ASSERT(visitor != NULL);
@@ skipping 25 matching lines @@
     }
   }
 
   ProcessedSampleBuffer* BuildProcessedSampleBuffer(SampleFilter* filter);
 
  private:
   ProcessedSample* BuildProcessedSample(Sample* sample,
                                         const CodeLookupTable& clt);
   Sample* Next(Sample* sample);
 
+  VirtualMemory* memory_;
   Sample* samples_;
   intptr_t capacity_;
   uintptr_t cursor_;
 
   DISALLOW_COPY_AND_ASSIGN(SampleBuffer);
 };
 
 
 // A |ProcessedSample| is a combination of 1 (or more) |Sample|(s) that have
 // been merged into a logical sample. The raw data may have been processed to
@@ skipping 111 matching lines @@
  private:
   ZoneGrowableArray<ProcessedSample*> samples_;
   CodeLookupTable* code_lookup_table_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessedSampleBuffer);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_PROFILER_H_