- Remove heap tracing.

runtime/vm/pages.cc

Index: runtime/vm/pages.cc
===================================================================
--- runtime/vm/pages.cc	(revision 21785)
+++ runtime/vm/pages.cc	(working copy)
@@ -8,7 +8,6 @@
 #include "vm/compiler_stats.h"
 #include "vm/gc_marker.h"
 #include "vm/gc_sweeper.h"
-#include "vm/heap_trace.h"
 #include "vm/object.h"
 #include "vm/virtual_memory.h"
 
@@ -408,10 +407,6 @@
   Isolate* isolate = Isolate::Current();
   NoHandleScope no_handles(isolate);
 
-  if (HeapTrace::is_enabled()) {
-    isolate->heap()->trace()->TraceMarkSweepStart();
-  }
-
   if (FLAG_print_free_list_before_gc) {
     OS::Print("Data Freelist (before GC):\n");
     freelist_[HeapPage::kData].Print();
@@ -503,10 +498,6 @@
     OS::PrintErr(" done.\n");
   }
 
-  if (HeapTrace::is_enabled()) {
-    isolate->heap()->trace()->TraceMarkSweepFinish();
-  }
-
   // Done, reset the marker.
   ASSERT(sweeping_);
   sweeping_ = false;