[debug] Introduce GetCreationContext to debug API

This new function forwards to v8::Object::CreationContext but has
special handling for JSGlobalProxy objects to prevent the former from
crashing.

R=yangguo@chromium.org

Bug: chromium:952057
Change-Id: I5ade682976efd1724c13f52b468e4fb30bb9ade7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1569425
Commit-Queue: Simon Zünd <szuend@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61197}

src/api.cc

@@ -9100,6 +9100,14 @@ MaybeLocal<Array> debug::GetPrivateFields(Local<Context> context,
   RETURN_ESCAPED(Utils::ToLocal(result));
 }
 
+Local<Context> debug::GetCreationContext(Local<Object> value) {
+  i::Handle<i::Object> val = Utils::OpenHandle(*value);
+  if (val->IsJSGlobalProxy()) {
+    return Local<Context>();
+  }
+  return value->CreationContext();
+}
+
 void debug::ChangeBreakOnException(Isolate* isolate, ExceptionBreakState type) {
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(isolate);
   internal_isolate->debug()->ChangeBreakOnException(

src/debug/debug-interface.h

@@ -57,6 +57,12 @@ MaybeLocal<Array> GetInternalProperties(Isolate* isolate, Local<Value> value);
 V8_EXPORT_PRIVATE MaybeLocal<Array> GetPrivateFields(Local<Context> context,
                                                      Local<Object> value);
 
+/**
+ * Forwards to v8::Object::CreationContext, but with special handling for
+ * JSGlobalProxy objects.
+ */
+Local<Context> GetCreationContext(Local<Object> value);
+
 enum ExceptionBreakState {
   NoBreakOnException = 0,
   BreakOnUncaughtException = 1,

src/inspector/v8-debugger.cc

@@ -42,7 +42,8 @@ class MatchPrototypePredicate : public v8::debug::QueryObjectPredicate {
       : m_inspector(inspector), m_context(context), m_prototype(prototype) {}
 
   bool Filter(v8::Local<v8::Object> object) override {
-    v8::Local<v8::Context> objectContext = object->CreationContext();
+    v8::Local<v8::Context> objectContext =
+        v8::debug::GetCreationContext(object);
     if (objectContext != m_context) return false;
     if (!m_inspector->client()->isInspectableHeapObject(object)) return false;
     // Get prototype chain for current object until first visited prototype.