[ES6 modules] Minor fixes to v8::ScriptModule

third_party/WebKit/Source/bindings/core/v8/ScriptModule.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 "bindings/core/v8/ScriptModule.h"
 
 #include "bindings/core/v8/V8Binding.h"
 #include "core/dom/Modulator.h"
 #include "core/dom/ScriptModuleResolver.h"
 
@@ skipping 24 matching lines @@
     DCHECK(try_catch.HasCaught());
     return ScriptModule();
   }
   DCHECK(!try_catch.HasCaught());
   return ScriptModule(isolate, module);
 }
 
 ScriptValue ScriptModule::Instantiate(ScriptState* script_state) {
   v8::Isolate* isolate = script_state->GetIsolate();
   v8::TryCatch try_catch(isolate);
+  try_catch.SetVerbose(true);
 
   DCHECK(!IsNull());
   v8::Local<v8::Context> context = script_state->GetContext();
   bool success = module_->NewLocal(script_state->GetIsolate())
                      ->Instantiate(context, &ResolveModuleCallback);
   if (!success) {
     DCHECK(try_catch.HasCaught());
     return ScriptValue(script_state, try_catch.Exception());
   }
   DCHECK(!try_catch.HasCaught());
   return ScriptValue();
 }
 
-void ScriptModule::Evaluate(ScriptState* script_state) {
+void ScriptModule::Evaluate(ScriptState* script_state) const {
   v8::Isolate* isolate = script_state->GetIsolate();
+
+  // Isolate exceptions that occur when executing the code. These exceptions
+  // should not interfere with javascript code we might evaluate from C++ when
+  // returning from here.
   v8::TryCatch try_catch(isolate);
   try_catch.SetVerbose(true);
+
+  // TODO(kouhei): We currently don't have a code-path which use return value of
+  // EvaluateModule. Stop ignoring result once we have such path.
   v8::Local<v8::Value> result;
   if (!V8Call(
           V8ScriptRunner::EvaluateModule(module_->NewLocal(isolate),
                                          script_state->GetContext(), isolate),
           result, try_catch)) {
-    // TODO(adamk): report error
+    return;
   }
 }
 
 Vector<String> ScriptModule::ModuleRequests(ScriptState* script_state) {
   if (IsNull())
     return Vector<String>();
 
   v8::Local<v8::Module> module = module_->NewLocal(script_state->GetIsolate());
 
   Vector<String> ret;
@@ skipping 23 matching lines @@
   if (resolved.IsNull()) {
     DCHECK(exception_state.HadException());
     return v8::MaybeLocal<v8::Module>();
   }
 
   DCHECK(!exception_state.HadException());
   return v8::MaybeLocal<v8::Module>(resolved.module_->NewLocal(isolate));
 }
 
 }  // namespace blink