Introduce API to trigger exception on JS execution.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6497 matching lines @@
 }
 
 
 void Isolate::Exit() {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   isolate->Exit();
 }
 
 
 Isolate::DisallowJavascriptExecutionScope::DisallowJavascriptExecutionScope(
-    Isolate* isolate) {
+    Isolate* isolate,
+    Isolate::DisallowJavascriptExecutionScope::OnFailure on_failure)
+    : on_failure_(on_failure) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  internal_ = reinterpret_cast<void*>(
-      new i::DisallowJavascriptExecution(i_isolate));
+  if (on_failure_ == CRASH_ON_FAILURE) {
+    internal_ = reinterpret_cast<void*>(
+        new i::DisallowJavascriptExecution(i_isolate));
+  } else {
+    ASSERT_EQ(THROW_ON_FAILURE, on_failure);
+    internal_ = reinterpret_cast<void*>(
+        new i::ThrowOnJavascriptExecution(i_isolate));
+  }
 }
 
 
 Isolate::DisallowJavascriptExecutionScope::~DisallowJavascriptExecutionScope() {
-  delete reinterpret_cast<i::DisallowJavascriptExecution*>(internal_);
+  if (on_failure_ == CRASH_ON_FAILURE) {
+    delete reinterpret_cast<i::DisallowJavascriptExecution*>(internal_);
+  } else {
+    delete reinterpret_cast<i::ThrowOnJavascriptExecution*>(internal_);
+  }
 }
 
 
 Isolate::AllowJavascriptExecutionScope::AllowJavascriptExecutionScope(
     Isolate* isolate) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  internal_ = reinterpret_cast<void*>(
+  internal_assert_ = reinterpret_cast<void*>(
       new i::AllowJavascriptExecution(i_isolate));
+  internal_throws_ = reinterpret_cast<void*>(
+      new i::NoThrowOnJavascriptExecution(i_isolate));
 }
 
 
 Isolate::AllowJavascriptExecutionScope::~AllowJavascriptExecutionScope() {
-  delete reinterpret_cast<i::AllowJavascriptExecution*>(internal_);
+  delete reinterpret_cast<i::AllowJavascriptExecution*>(internal_assert_);
+  delete reinterpret_cast<i::NoThrowOnJavascriptExecution*>(internal_throws_);
 }
 
 
 void Isolate::GetHeapStatistics(HeapStatistics* heap_statistics) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   if (!isolate->IsInitialized()) {
     heap_statistics->total_heap_size_ = 0;
     heap_statistics->total_heap_size_executable_ = 0;
     heap_statistics->total_physical_size_ = 0;
     heap_statistics->used_heap_size_ = 0;
@@ skipping 978 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal