1. Fix memory leaks reported by running a simple test using ASAN

runtime/vm/thread.cc

 // Copyright (c) 2015, 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/thread.h"
 
 #include "vm/dart_api_state.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
 #include "vm/log.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 #include "vm/os_thread.h"
 #include "vm/profiler.h"
 #include "vm/runtime_entry.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 #include "vm/thread_interrupter.h"
 #include "vm/thread_registry.h"
 
 namespace dart {
 
 Thread::~Thread() {
   // We should cleanly exit any isolate before destruction.
   ASSERT(isolate_ == NULL);
+  // There should be no top api scopes at this point.
+  ASSERT(api_top_scope() == NULL);
+  // Delete the resusable api scope if there is one.
+  if (api_reusable_scope_) {
+    delete api_reusable_scope_;
+    api_reusable_scope_ = NULL;
+  }
+  delete thread_lock_;
+  thread_lock_ = NULL;
 }
 
 
 #if defined(DEBUG)
 #define REUSABLE_HANDLE_SCOPE_INIT(object)                                     \
   reusable_##object##_handle_scope_active_(false),
 #else
 #define REUSABLE_HANDLE_SCOPE_INIT(object)
 #endif  // defined(DEBUG)
 
@@ skipping 458 matching lines @@
 
 DisableThreadInterruptsScope::~DisableThreadInterruptsScope() {
   if (thread() != NULL) {
     OSThread* os_thread = thread()->os_thread();
     ASSERT(os_thread != NULL);
     os_thread->EnableThreadInterrupts();
   }
 }
 
 }  // namespace dart