[inspector] Disable [[Scopes]] internal property

We don't remove the code just yet in case we need to re-enable the
feature. This could be in case we discover workflows not covered by
the "Scope View" and the scopes we report on "Debugger.paused".

R=kimanh@chromium.org

Bug: chromium:1365858
Change-Id: I636cc861af932156944a3f6e0a149cce0f939329
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3905185
Reviewed-by: Kim-Anh Tran <kimanh@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83379}

src/debug/debug-interface.cc

@@ -1434,6 +1434,10 @@ bool isExperimentalAsyncStackTaggingApiEnabled() {
   return i::v8_flags.experimental_async_stack_tagging_api;
 }
 
+bool isExperimentalRemoveInternalScopesPropertyEnabled() {
+  return i::v8_flags.experimental_remove_internal_scopes_property;
+}
+
 void RecordAsyncStackTaggingCreateTaskCall(v8::Isolate* v8_isolate) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   isolate->CountUsage(v8::Isolate::kAsyncStackTaggingCreateTaskCall);

src/debug/debug-interface.h

@@ -732,6 +732,7 @@ AccessorPair* AccessorPair::Cast(v8::Value* value) {
 MaybeLocal<Message> GetMessageFromPromise(Local<Promise> promise);
 
 bool isExperimentalAsyncStackTaggingApiEnabled();
+bool isExperimentalRemoveInternalScopesPropertyEnabled();
 
 void RecordAsyncStackTaggingCreateTaskCall(v8::Isolate* isolate);
 

src/flags/flag-definitions.h

@@ -1701,6 +1701,8 @@ DEFINE_BOOL(experimental_value_unavailable, false,
 DEFINE_BOOL(
     live_edit_top_frame, true,
     "enable support for live-editing the top-most function on the stack")
+DEFINE_BOOL(experimental_remove_internal_scopes_property, true,
+            "don't report the artificial [[Scopes]] property for functions")
 
 // disassembler
 DEFINE_BOOL(log_colour, ENABLE_LOG_COLOUR,

src/inspector/v8-debugger.cc

@@ -786,6 +786,11 @@ v8::MaybeLocal<v8::Array> V8Debugger::internalProperties(
                        toV8StringInternalized(m_isolate, "[[Entries]]"));
     createDataProperty(context, properties, properties->Length(), entries);
   }
+
+  if (v8::debug::isExperimentalRemoveInternalScopesPropertyEnabled()) {
+    return properties;
+  }
+
   if (value->IsGeneratorObject()) {
     v8::Local<v8::Value> scopes;
     if (generatorScopes(context, value).ToLocal(&scopes)) {

test/inspector/debugger/suspended-generator-scopes.js

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Flags: --no-experimental-remove-internal-scopes-property
+
 let {session, contextGroup, Protocol} = InspectorTest.start('Tests that suspended generators produce scopes');
 
 contextGroup.addScript(`

test/inspector/regress/regress-crbug-1246896.js

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Flags: --no-experimental-remove-internal-scopes-property
+
 const {Protocol} = InspectorTest.start('Don\'t crash when getting the properties of a native function');
 
 (async () => {

test/inspector/runtime/function-scopes.js

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Flags: --no-experimental-remove-internal-scopes-property
+
 let {session, contextGroup, Protocol} = InspectorTest.start('Checks [[Scopes]] for functions');
 
 contextGroup.addScript(`

test/inspector/runtime/internal-properties.js

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Flags: --no-experimental-remove-internal-scopes-property
+
 let {session, contextGroup, Protocol} = InspectorTest.start('Checks internal properties in Runtime.getProperties output');
 
 contextGroup.addScript(`