Fix issue 738: make compilable with profilingsupport=off

src/heap-profiler.cc

Index: src/heap-profiler.cc
diff --git a/src/heap-profiler.cc b/src/heap-profiler.cc
index ea17abc33d930dbf2dc2e2fcb755a063eb4380d6..55f09b92831f87e93a3338f1595b07b213b5a676 100644
--- a/src/heap-profiler.cc
+++ b/src/heap-profiler.cc
@@ -326,20 +326,27 @@ HeapProfiler::~HeapProfiler() {
   delete snapshots_;
 }
 
+#endif  // ENABLE_LOGGING_AND_PROFILING
 
 void HeapProfiler::Setup() {
+#ifdef ENABLE_LOGGING_AND_PROFILING
   if (singleton_ == NULL) {
     singleton_ = new HeapProfiler();
   }
+#endif
 }
 
 
 void HeapProfiler::TearDown() {
+#ifdef ENABLE_LOGGING_AND_PROFILING
   delete singleton_;
   singleton_ = NULL;
+#endif
 }
 
 
+#ifdef ENABLE_LOGGING_AND_PROFILING
+
 HeapSnapshot* HeapProfiler::TakeSnapshot(const char* name) {
   ASSERT(singleton_ != NULL);
   return singleton_->TakeSnapshotImpl(name);