Remove "--wasm-disable-structured-cloning" flag

Bug: v8:10021
Change-Id: I23a693064c44cd620a874787bcc00cb42bc5874f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1999158
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Ben Smith <binji@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65933}

src/flags/flag-definitions.h

@@ -656,8 +656,6 @@ DEFINE_BOOL(untrusted_code_mitigations, V8_DEFAULT_UNTRUSTED_CODE_MITIGATIONS,
 DEFINE_BOOL(expose_wasm, true, "expose wasm interface to JavaScript")
 DEFINE_BOOL(assume_asmjs_origin, false,
             "force wasm decoder to assume input is internal asm-wasm format")
-DEFINE_BOOL(wasm_disable_structured_cloning, false,
-            "disable wasm structured cloning")
 DEFINE_INT(wasm_num_compilation_tasks, 128,
            "maximum number of parallel compilation tasks for wasm")
 DEFINE_DEBUG_BOOL(trace_wasm_native_heap, false,

src/objects/value-serializer.cc

@@ -557,15 +557,8 @@ Maybe<bool> ValueSerializer::WriteJSReceiver(Handle<JSReceiver> receiver) {
       return WriteJSArrayBufferView(JSArrayBufferView::cast(*receiver));
     case JS_ERROR_TYPE:
       return WriteJSError(Handle<JSObject>::cast(receiver));
-    case WASM_MODULE_OBJECT_TYPE: {
-      auto enabled_features = wasm::WasmFeatures::FromIsolate(isolate_);
-      if (!FLAG_wasm_disable_structured_cloning ||
-          enabled_features.has_threads()) {
-        // Only write WebAssembly modules if not disabled by a flag.
-        return WriteWasmModule(Handle<WasmModuleObject>::cast(receiver));
-      }
-      break;
-    }
+    case WASM_MODULE_OBJECT_TYPE:
+      return WriteWasmModule(Handle<WasmModuleObject>::cast(receiver));
     case WASM_MEMORY_OBJECT_TYPE: {
       auto enabled_features = wasm::WasmFeatures::FromIsolate(isolate_);
       if (enabled_features.has_threads()) {
@@ -1911,11 +1904,6 @@ MaybeHandle<Object> ValueDeserializer::ReadJSError() {
 }
 
 MaybeHandle<JSObject> ValueDeserializer::ReadWasmModuleTransfer() {
-  auto enabled_features = wasm::WasmFeatures::FromIsolate(isolate_);
-  if (FLAG_wasm_disable_structured_cloning && !enabled_features.has_threads()) {
-    return MaybeHandle<JSObject>();
-  }
-
   uint32_t transfer_id = 0;
   Local<Value> module_value;
   if (!ReadVarint<uint32_t>().To(&transfer_id) || delegate_ == nullptr ||

test/mjsunit/regress/wasm/regress-8059.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --no-wasm-disable-structured-cloning
-
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 (function TestPostModule() {

test/mjsunit/regress/wasm/regress-8533.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --no-wasm-disable-structured-cloning --allow-natives-syntax --experimental-wasm-threads
+// Flags: --allow-natives-syntax --experimental-wasm-threads
 
 load('test/mjsunit/wasm/wasm-module-builder.js');
 

test/mjsunit/wasm/worker-interpreter.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --no-wasm-disable-structured-cloning --expose-gc
+// Flags: --allow-natives-syntax --expose-gc
 
 load("test/mjsunit/wasm/wasm-module-builder.js");
 

test/mjsunit/wasm/worker-module.js

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --no-wasm-disable-structured-cloning
-
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 (function TestPostModule() {