Update heap test so it calls gc 6 times. This is necessary to avoid flakiness.

test/cctest/test-heap-profiler.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 //
 // Tests for heap profiler
 
 #include <ctype.h>
 
 #include "v8.h"
 
 #include "cctest.h"
 #include "hashmap.h"
@@ skipping 696 matching lines @@
   CHECK_EQ(1, stream.eos_signaled());
   return stream;
 }
 
 
 TEST(HeapSnapshotObjectsStats) {
   v8::HandleScope scope;
   LocalContext env;
 
   v8::HeapProfiler::StartHeapObjectsTracking();
-  // We have to call GC 5 times. In other case the garbage will be
+  // We have to call GC 6 times. In other case the garbage will be
   // the reason of flakiness.
-  for (int i = 0; i < 5; ++i) {
+  for (int i = 0; i < 6; ++i) {
     HEAP->CollectAllGarbage(i::Heap::kNoGCFlags);
   }
 
   v8::SnapshotObjectId initial_id;
   {
     // Single chunk of data expected in update. Initial data.
     TestStatsStream stats_update = GetHeapStatsUpdate(&initial_id);
     CHECK_EQ(1, stats_update.intervals_count());
     CHECK_EQ(1, stats_update.updates_written());
     CHECK_LT(0, stats_update.entries_size());
@@ skipping 889 matching lines @@
   const v8::HeapGraphNode* global_object =
       GetProperty(global, v8::HeapGraphEdge::kProperty, "global_object");
   CHECK_NE(NULL, global_object);
   const v8::HeapGraphNode* properties =
       GetProperty(global_object, v8::HeapGraphEdge::kInternal, "properties");
   CHECK_EQ(NULL, properties);
   const v8::HeapGraphNode* elements =
       GetProperty(global_object, v8::HeapGraphEdge::kInternal, "elements");
   CHECK_EQ(NULL, elements);
 }