More set_map() calls replaced with MigrateToMap().

src/bootstrapper.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
 #include "src/extensions/free-buffer-extension.h"
@@ skipping 324 matching lines @@
   Handle<Context> env = genesis.result();
   if (env.is_null() || !InstallExtensions(env, extensions)) {
     return Handle<Context>();
   }
   return scope.CloseAndEscape(env);
 }
 
 
 static void SetObjectPrototype(Handle<JSObject> object, Handle<Object> proto) {
   // object.__proto__ = proto;
-  Handle<Map> old_to_map = Handle<Map>(object->map());
-  Handle<Map> new_to_map = Map::Copy(old_to_map);
-  new_to_map->set_prototype(*proto);
-  object->set_map(*new_to_map);
+  Handle<Map> old_map = Handle<Map>(object->map());
+  Handle<Map> new_map = Map::Copy(old_map);
+  new_map->set_prototype(*proto);
+  JSObject::MigrateToMap(object, new_map);
 }
 
 
 void Bootstrapper::DetachGlobal(Handle<Context> env) {
   Factory* factory = env->GetIsolate()->factory();
   Handle<JSGlobalProxy> global_proxy(JSGlobalProxy::cast(env->global_proxy()));
   global_proxy->set_native_context(*factory->null_value());
   SetObjectPrototype(global_proxy, factory->null_value());
 }
 
@@ skipping 2174 matching lines @@
 void Genesis::TransferObject(Handle<JSObject> from, Handle<JSObject> to) {
   HandleScope outer(isolate());
 
   ASSERT(!from->IsJSArray());
   ASSERT(!to->IsJSArray());
 
   TransferNamedProperties(from, to);
   TransferIndexedProperties(from, to);
 
   // Transfer the prototype (new map is needed).
-  Handle<Map> old_to_map = Handle<Map>(to->map());
-  Handle<Map> new_to_map = Map::Copy(old_to_map);
-  new_to_map->set_prototype(from->map()->prototype());
-  to->set_map(*new_to_map);
+  Handle<Object> proto(from->map()->prototype(), isolate());
+  SetObjectPrototype(to, proto);
 }
 
 
 void Genesis::MakeFunctionInstancePrototypeWritable() {
   // The maps with writable prototype are created in CreateEmptyFunction
   // and CreateStrictModeFunctionMaps respectively. Initially the maps are
   // created with read-only prototype for JS builtins processing.
   ASSERT(!sloppy_function_map_writable_prototype_.is_null());
   ASSERT(!strict_function_map_writable_prototype_.is_null());
 
@@ skipping 185 matching lines @@
   return from + sizeof(NestingCounterType);
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   ASSERT(!IsActive());
 }
 
 } }  // namespace v8::internal