[debugger] simplify fetching scripts for inspector.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index ad41d819b7f094ddda7834f5ca57377ae8184f03..ccc6266a98313b41501d7728c9c70328acf2c0f2 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -8946,13 +8946,21 @@ void DebugInterface::GetLoadedScripts(
     PersistentValueVector<DebugInterface::Script>& scripts) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   ENTER_V8(isolate);
-  i::HandleScope handle_scope(isolate);
-  i::Handle<i::FixedArray> instances = isolate->debug()->GetLoadedScripts();
-  for (int i = 0; i < instances->length(); i++) {
-    i::Handle<i::Script> script =
-        i::Handle<i::Script>(i::Script::cast(instances->get(i)));
-    if (script->type() != i::Script::TYPE_NORMAL) continue;
-    scripts.Append(ToApiHandle<Script>(script));
+  // TODO(kozyatinskiy): remove this GC once tests are dealt with.
+  isolate->heap()->CollectAllGarbage(i::Heap::kFinalizeIncrementalMarkingMask,
+                                     i::GarbageCollectionReason::kDebugger);
+  {
+    i::DisallowHeapAllocation no_gc;
+    i::Script::Iterator iterator(isolate);
+    i::Script* script;
+    while ((script = iterator.Next())) {
+      if (script->type() != i::Script::TYPE_NORMAL) continue;
+      if (script->HasValidSource()) {
+        i::HandleScope handle_scope(isolate);
+        i::Handle<i::Script> script_handle(script, isolate);
+        scripts.Append(ToApiHandle<Script>(script_handle));
+      }
+    }
   }
 }