[hot reload] Ensure old class table is also freed on success.

runtime/vm/isolate_reload.cc

 // Copyright (c) 2016, 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/isolate_reload.h"
 
 #include "vm/become.h"
 #include "vm/bit_vector.h"
 #include "vm/runtime_entry.h"
 #include "vm/compiler.h"
@@ skipping 455 matching lines @@
       saved_libraries_(GrowableObjectArray::null()),
       root_url_prefix_(String::null()),
       old_root_url_prefix_(String::null()) {
   // NOTE: DO NOT ALLOCATE ANY RAW OBJECTS HERE. The IsolateReloadContext is not
   // associated with the isolate yet and if a GC is triggered here the raw
   // objects will not be properly accounted for.
   ASSERT(zone_ != NULL);
 }
 
 
-IsolateReloadContext::~IsolateReloadContext() {}
+IsolateReloadContext::~IsolateReloadContext() {
+  ASSERT(saved_class_table_ == NULL);
+}
 
 
 void IsolateReloadContext::ReportError(const Error& error) {
   if (FLAG_trace_reload) {
     THR_Print("ISO-RELOAD: Error: %s\n", error.ToErrorCString());
   }
   ServiceEvent service_event(I, ServiceEvent::kIsolateReload);
   service_event.set_reload_error(&error);
   Service::HandleEvent(&service_event);
 }
@@ skipping 655 matching lines @@
   TIMELINE_SCOPE(Commit);
   TIR_Print("---- COMMITTING RELOAD\n");
 
   // Note that the object heap contains before and after instances
   // used for morphing. It is therefore important that morphing takes
   // place prior to any heap walking.
   // So please keep this code at the top of Commit().
   if (HasInstanceMorphers()) {
     // Perform shape shifting of instances if necessary.
     MorphInstances();
+  } else {
+    free(saved_class_table_);
+    saved_class_table_ = NULL;
   }
 
 #ifdef DEBUG
   VerifyMaps();
 #endif
 
   {
     TIMELINE_SCOPE(CopyStaticFieldsAndPatchFieldsAndFunctions);
     // Copy static field values from the old classes to the new classes.
     // Patch fields and functions in the old classes so that they retain
@@ skipping 736 matching lines @@
         ASSERT(!super_cls.IsNull());
         super_cls.AddDirectSubclass(cls);
       }
     }
   }
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart