Insert CHECK()s to ensure module-related code are not executed without the flag

third_party/WebKit/Source/core/dom/ModulatorImpl.cpp

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/ModulatorImpl.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/dom/ModuleMap.h"
 #include "core/dom/ModuleScript.h"
@@ skipping 59 matching lines @@
   // Step 2. When the internal module script graph fetching procedure
   // asynchronously completes with result, asynchronously complete this
   // algorithm with result.
   // Note: We delegate to ModuleTreeLinker to notify ModuleTreeClient.
 }
 
 void ModulatorImpl::FetchTreeInternal(const ModuleScriptFetchRequest& request,
                                       const AncestorList& ancestor_list,
                                       ModuleGraphLevel level,
                                       ModuleTreeClient* client) {
+  // We ensure module-related code is not executed without the flag.
+  // https://crbug.com/715376
+  CHECK(RuntimeEnabledFeatures::moduleScriptsEnabled());
+
   tree_linker_registry_->Fetch(request, ancestor_list, level, this, client);
 }
 
 void ModulatorImpl::FetchSingle(const ModuleScriptFetchRequest& request,
                                 ModuleGraphLevel level,
                                 SingleModuleClient* client) {
+  // We ensure module-related code is not executed without the flag.
+  // https://crbug.com/715376
+  CHECK(RuntimeEnabledFeatures::moduleScriptsEnabled());
+
   map_->FetchSingleModuleScript(request, level, client);
 }
 
 void ModulatorImpl::FetchNewSingleModule(
     const ModuleScriptFetchRequest& request,
     ModuleGraphLevel level,
     ModuleScriptLoaderClient* client) {
+  // We ensure module-related code is not executed without the flag.
+  // https://crbug.com/715376
+  CHECK(RuntimeEnabledFeatures::moduleScriptsEnabled());
+
   loader_registry_->Fetch(request, level, this, fetcher_.Get(), client);
 }
 
 ModuleScript* ModulatorImpl::GetFetchedModuleScript(const KURL& url) {
   return map_->GetFetchedModuleScript(url);
 }
 
 ScriptModule ModulatorImpl::CompileModule(
     const String& provided_source,
     const String& url_str,
@@ skipping 31 matching lines @@
   return script_module.ModuleRequests(script_state_.Get());
 }
 
 inline ExecutionContext* ModulatorImpl::GetExecutionContext() const {
   return ExecutionContext::From(script_state_.Get());
 }
 
 void ModulatorImpl::ExecuteModule(const ModuleScript* module_script) {
   // https://html.spec.whatwg.org/#run-a-module-script
 
+  // We ensure module-related code is not executed without the flag.
+  // https://crbug.com/715376
+  CHECK(RuntimeEnabledFeatures::moduleScriptsEnabled());
+
   // 1. "Let settings be the settings object of s."
   // The settings object is |this|.
 
   // 2. "Check if we can run script with settings.
   //     If this returns "do not run" then abort these steps."
   if (!GetExecutionContext()->CanExecuteScripts(kAboutToExecuteScript))
     return;
 
   // 6. "Prepare to run script given settings."
   // This is placed here to also cover ScriptModule::ReportException().
@@ skipping 33 matching lines @@
   visitor->Trace(loader_registry_);
   visitor->Trace(tree_linker_registry_);
   visitor->Trace(script_module_resolver_);
 }
 
 DEFINE_TRACE_WRAPPERS(ModulatorImpl) {
   visitor->TraceWrappers(map_);
 }
 
 }  // namespace blink