When unwraping handles, verify only if --verify_handles. Fixes issue 11265,

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, 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 "include/dart_api.h"
 
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
@@ skipping 16 matching lines @@
 #include "vm/stack_frame.h"
 #include "vm/symbols.h"
 #include "vm/timer.h"
 #include "vm/unicode.h"
 #include "vm/verifier.h"
 #include "vm/version.h"
 
 namespace dart {
 
 DECLARE_FLAG(bool, print_class_table);
+DECLARE_FLAG(bool, verify_handles);
 
 ThreadLocalKey Api::api_native_key_ = Thread::kUnsetThreadLocalKey;
 Dart_Handle Api::true_handle_ = NULL;
 Dart_Handle Api::false_handle_ = NULL;
 Dart_Handle Api::null_handle_ = NULL;
 
 
 const char* CanonicalFunction(const char* func) {
   if (strncmp(func, "dart::", 6) == 0) {
     return func + 6;
@@ skipping 43 matching lines @@
   ref->set_raw(raw);
   return reinterpret_cast<Dart_Handle>(ref);
 }
 
 RawObject* Api::UnwrapHandle(Dart_Handle object) {
 #if defined(DEBUG)
   Isolate* isolate = Isolate::Current();
   ASSERT(isolate != NULL);
   ApiState* state = isolate->api_state();
   ASSERT(state != NULL);
-  ASSERT(state->IsValidLocalHandle(object) ||
+  ASSERT(!FLAG_verify_handles ||
+         state->IsValidLocalHandle(object) ||
          Dart::vm_isolate()->api_state()->IsValidLocalHandle(object));
   ASSERT(FinalizablePersistentHandle::raw_offset() == 0 &&
          PersistentHandle::raw_offset() == 0 &&
          LocalHandle::raw_offset() == 0);
 #endif
   return (reinterpret_cast<LocalHandle*>(object))->raw();
 }
 
 #define DEFINE_UNWRAP(type)                                                    \
   const type& Api::Unwrap##type##Handle(Isolate* iso,                          \
@@ skipping 4748 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success();
 }
 
 }  // namespace dart