Add flag to control number of stack frames collected by profiler

runtime/vm/profiler_test.cc

 // 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.
 
 #include "platform/assert.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
 #include "vm/globals.h"
 #include "vm/profiler.h"
 #include "vm/unit_test.h"
 
 namespace dart {
 
 class ProfileSampleBufferTestHelper {
  public:
   static intptr_t IterateCount(const Isolate* isolate,
                                const SampleBuffer& sample_buffer) {
     intptr_t c = 0;
+    Sample* sample = Sample::Allocate();
     for (intptr_t i = 0; i < sample_buffer.capacity(); i++) {
-      Sample sample = sample_buffer.GetSample(i);
-      if (sample.isolate != isolate) {
+      sample_buffer.CopySample(i, sample);
+      if (sample->isolate != isolate) {
         continue;
       }
       c++;
     }
+    free(sample);
     return c;
   }
 
 
   static intptr_t IterateSumPC(const Isolate* isolate,
                                const SampleBuffer& sample_buffer) {
     intptr_t c = 0;
+    Sample* sample = Sample::Allocate();
     for (intptr_t i = 0; i < sample_buffer.capacity(); i++) {
-      Sample sample = sample_buffer.GetSample(i);
-      if (sample.isolate != isolate) {
+      sample_buffer.CopySample(i, sample);
+      if (sample->isolate != isolate) {
         continue;
       }
-      c += sample.pcs[0];
+      c += sample->pcs[0];
     }
+    free(sample);
     return c;
   }
 };
 
 
 TEST_CASE(ProfilerSampleBufferWrapTest) {
   SampleBuffer* sample_buffer = new SampleBuffer(3);
   Isolate* i = reinterpret_cast<Isolate*>(0x1);
   EXPECT_EQ(0, ProfileSampleBufferTestHelper::IterateSumPC(i, *sample_buffer));
   Sample* s;
@@ skipping 31 matching lines @@
   s = sample_buffer->ReserveSample();
   s->isolate = i;
   EXPECT_EQ(3, ProfileSampleBufferTestHelper::IterateCount(i, *sample_buffer));
   s = sample_buffer->ReserveSample();
   s->isolate = i;
   EXPECT_EQ(3, ProfileSampleBufferTestHelper::IterateCount(i, *sample_buffer));
   delete sample_buffer;
 }
 
 }  // namespace dart