Migrate most uses of StackZone(Isolate*) to Thread*.

runtime/vm/gc_marker.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/gc_marker.h"
 
 #include <map>
 #include <utility>
 #include <vector>
 
@@ skipping 513 matching lines @@
 
 void GCMarker::MarkObjects(Isolate* isolate,
                            PageSpace* page_space,
                            bool invoke_api_callbacks,
                            bool collect_code) {
   const bool visit_function_code = !collect_code;
   Prologue(isolate, invoke_api_callbacks);
   // The API prologue/epilogue may create/destroy zones, so we must not
   // depend on zone allocations surviving beyond the epilogue callback.
   {
-    StackZone zone(isolate);
+    StackZone zone(Thread::Current());
     MarkingStack marking_stack;
     DelaySet delay_set;
     MarkingVisitor mark(isolate, heap_, page_space, &marking_stack,
                         &delay_set, visit_function_code);
     IterateRoots(isolate, &mark, !invoke_api_callbacks);
     mark.DrainMarkingStack();
     IterateWeakReferences(isolate, &mark);
     MarkingWeakVisitor mark_weak;
     IterateWeakRoots(isolate, &mark_weak, invoke_api_callbacks);
     // TODO(koda): Add hand-over callback and centralize skipped code functions.
     marked_bytes_ = mark.marked_bytes();
     mark.Finalize();
     delay_set.ClearReferences();
     ProcessWeakTables(page_space);
     ProcessObjectIdTable(isolate);
   }
   Epilogue(isolate, invoke_api_callbacks);
 }
 
 }  // namespace dart