- Remove heap tracing.

runtime/vm/gc_sweeper.cc

Index: runtime/vm/gc_sweeper.cc
===================================================================
--- runtime/vm/gc_sweeper.cc	(revision 21785)
+++ runtime/vm/gc_sweeper.cc	(working copy)
@@ -7,7 +7,6 @@
 #include "vm/freelist.h"
 #include "vm/globals.h"
 #include "vm/heap.h"
-#include "vm/heap_trace.h"
 #include "vm/pages.h"
 
 namespace dart {
@@ -30,7 +29,7 @@
 
   while (current < end) {
     intptr_t obj_size;
-    if (in_use_swept == in_use && !HeapTrace::is_enabled()) {
+    if (in_use_swept == in_use) {
       // No more marked objects will be found on this page.
       obj_size = end - current;
       freelist->Free(current, obj_size);
@@ -44,18 +43,12 @@
       in_use_swept += obj_size;
     } else {
       uword free_end = current + raw_obj->Size();
-      if (HeapTrace::is_enabled()) {
-        heap_->trace()->TraceSweep(current);
-      }
       while (free_end < end) {
         RawObject* next_obj = RawObject::FromAddr(free_end);
         if (next_obj->IsMarked()) {
           // Reached the end of the free block.
           break;
         }
-        if (HeapTrace::is_enabled()) {
-          heap_->trace()->TraceSweep(free_end);
-        }
         // Expand the free block by the size of this object.
         free_end += next_obj->Size();
       }
@@ -75,9 +68,6 @@
 intptr_t GCSweeper::SweepLargePage(HeapPage* page) {
   RawObject* raw_obj = RawObject::FromAddr(page->object_start());
   if (!raw_obj->IsMarked()) {
-    if (HeapTrace::is_enabled()) {
-      heap_->trace()->TraceSweep(page->object_start());
-    }
     // The large object was not marked. Used size is zero, which also tells the
     // calling code that the large object page can be recycled.
     return 0;