Revert r32064, r32064 to fix Windows build.

runtime/vm/gc_marker.cc

Index: runtime/vm/gc_marker.cc
===================================================================
--- runtime/vm/gc_marker.cc	(revision 32064)
+++ runtime/vm/gc_marker.cc	(working copy)
@@ -6,7 +6,6 @@
 
 #include <map>
 #include <utility>
-#include <vector>
 
 #include "vm/allocation.h"
 #include "vm/dart_api_state.h"
@@ -160,7 +159,7 @@
       ASSERT(!raw_key->IsWatched());
       raw_key->SetWatchedBit();
     }
-    delay_set_.insert(DelaySet::value_type(raw_key, raw_weak));
+    delay_set_.insert(std::make_pair(raw_key, raw_weak));
   }
 
   void Finalize() {
@@ -194,14 +193,10 @@
       std::pair<DelaySet::iterator, DelaySet::iterator> ret;
       // Visit all elements with a key equal to raw_obj.
       ret = delay_set_.equal_range(raw_obj);
-      // Create a copy of the range in a temporary vector to iterate over it
-      // while delay_set_ may be modified.
-      std::vector<DelaySet::value_type> temp_copy(ret.first, ret.second);
-      delay_set_.erase(ret.first, ret.second);
-      for (std::vector<DelaySet::value_type>::iterator it = temp_copy.begin();
-           it != temp_copy.end(); ++it) {
+      for (DelaySet::iterator it = ret.first; it != ret.second; ++it) {
         it->second->VisitPointers(this);
       }
+      delay_set_.erase(ret.first, ret.second);
       raw_obj->ClearWatchedBit();
     }
     marking_stack_->Push(raw_obj);