[inspector] migrate Runtime to new style

src/inspector/injected-script.cc

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 36 matching lines @@
 #include "include/v8-inspector.h"
 
 namespace v8_inspector {
 
 using protocol::Array;
 using protocol::Runtime::PropertyDescriptor;
 using protocol::Runtime::InternalPropertyDescriptor;
 using protocol::Runtime::RemoteObject;
 using protocol::Maybe;
 
-static bool hasInternalError(ErrorString* errorString, bool hasError) {
-  if (hasError) *errorString = "Internal error";
-  return hasError;
-}
-
 std::unique_ptr<InjectedScript> InjectedScript::create(
     InspectedContext* inspectedContext) {
   v8::Isolate* isolate = inspectedContext->isolate();
   v8::HandleScope handles(isolate);
   v8::Local<v8::Context> context = inspectedContext->context();
   v8::Context::Scope scope(context);
 
   std::unique_ptr<InjectedScriptNative> injectedScriptNative(
       new InjectedScriptNative(isolate));
   v8::Local<v8::Object> scriptHostWrapper =
@@ skipping 45 matching lines @@
 
 InjectedScript::InjectedScript(
     InspectedContext* context, v8::Local<v8::Object> object,
     std::unique_ptr<InjectedScriptNative> injectedScriptNative)
     : m_context(context),
       m_value(context->isolate(), object),
       m_native(std::move(injectedScriptNative)) {}
 
 InjectedScript::~InjectedScript() {}
 
-void InjectedScript::getProperties(
-    ErrorString* errorString, v8::Local<v8::Object> object,
-    const String16& groupName, bool ownProperties, bool accessorPropertiesOnly,
-    bool generatePreview,
+Response InjectedScript::getProperties(
+    v8::Local<v8::Object> object, const String16& groupName, bool ownProperties,
+    bool accessorPropertiesOnly, bool generatePreview,
     std::unique_ptr<Array<PropertyDescriptor>>* properties,
     Maybe<protocol::Runtime::ExceptionDetails>* exceptionDetails) {
   v8::HandleScope handles(m_context->isolate());
   v8::Local<v8::Context> context = m_context->context();
   V8FunctionCall function(m_context->inspector(), m_context->context(),
                           v8Value(), "getProperties");
   function.appendArgument(object);
   function.appendArgument(groupName);
   function.appendArgument(ownProperties);
   function.appendArgument(accessorPropertiesOnly);
   function.appendArgument(generatePreview);
 
   v8::TryCatch tryCatch(m_context->isolate());
   v8::Local<v8::Value> resultValue = function.callWithoutExceptionHandling();
   if (tryCatch.HasCaught()) {
-    *exceptionDetails = createExceptionDetails(errorString, tryCatch, groupName,
-                                               generatePreview);
+    Response response = createExceptionDetails(
+        tryCatch, groupName, generatePreview, *exceptionDetails);
+    if (!response.isSuccess()) return response;
     // FIXME: make properties optional
     *properties = Array<PropertyDescriptor>::create();
-    return;
+    return Response::OK();
   }
-  if (hasInternalError(errorString, resultValue.IsEmpty())) return;
-  std::unique_ptr<protocol::Value> protocolValue =
-      toProtocolValue(errorString, context, resultValue);
-  if (!protocolValue) return;
-  protocol::ErrorSupport errors(errorString);
+  if (resultValue.IsEmpty()) return Response::InternalError();
+  std::unique_ptr<protocol::Value> protocolValue;
+  Response response =
+      toProtocolValue(context, resultValue, 1000, protocolValue);

[dgozman, 2016/11/02 19:54:00]

&protocolValue

[kozy, 2016/11/02 22:45:13]

Done.

+  if (!response.isSuccess()) return response;
+  protocol::ErrorSupport errors;
   std::unique_ptr<Array<PropertyDescriptor>> result =
       Array<PropertyDescriptor>::parse(protocolValue.get(), &errors);
-  if (!hasInternalError(errorString, errors.hasErrors()))
-    *properties = std::move(result);
+  if (errors.hasErrors()) return Response::Error(errors.errors());
+  *properties = std::move(result);
+  return Response::OK();
 }
 
 void InjectedScript::releaseObject(const String16& objectId) {
   std::unique_ptr<protocol::Value> parsedObjectId =
       protocol::parseJSON(objectId);
   if (!parsedObjectId) return;
   protocol::DictionaryValue* object =
       protocol::DictionaryValue::cast(parsedObjectId.get());
   if (!object) return;
   int boundId = 0;
   if (!object->getInteger("id", &boundId)) return;
   m_native->unbind(boundId);
 }
 
-std::unique_ptr<protocol::Runtime::RemoteObject> InjectedScript::wrapObject(
-    ErrorString* errorString, v8::Local<v8::Value> value,
-    const String16& groupName, bool forceValueType,
-    bool generatePreview) const {
+Response InjectedScript::wrapObject(
+    v8::Local<v8::Value> value, const String16& groupName, bool forceValueType,
+    bool generatePreview,
+    std::unique_ptr<protocol::Runtime::RemoteObject>& result) const {
   v8::HandleScope handles(m_context->isolate());
   v8::Local<v8::Value> wrappedObject;
   v8::Local<v8::Context> context = m_context->context();
-  if (!wrapValue(errorString, value, groupName, forceValueType, generatePreview)
-           .ToLocal(&wrappedObject))
-    return nullptr;
+  Response response = wrapValue(value, groupName, forceValueType,
+                                generatePreview, wrappedObject);
+  if (!response.isSuccess()) return response;
   protocol::ErrorSupport errors;
-  std::unique_ptr<protocol::Value> protocolValue =
-      toProtocolValue(errorString, context, wrappedObject);
-  if (!protocolValue) return nullptr;
+  std::unique_ptr<protocol::Value> protocolValue;
+  response = toProtocolValue(context, wrappedObject, 1000, protocolValue);
+  if (!response.isSuccess()) return response;
+
   std::unique_ptr<protocol::Runtime::RemoteObject> remoteObject =

[dgozman, 2016/11/02 19:53:59]

*result = ....

[kozy, 2016/11/02 22:45:12]

Done.

       protocol::Runtime::RemoteObject::parse(protocolValue.get(), &errors);
-  if (!remoteObject) *errorString = errors.errors();
-  return remoteObject;
+  if (!remoteObject) return Response::Error(errors.errors());
+  result = std::move(remoteObject);
+  return Response::OK();
 }
 
-bool InjectedScript::wrapObjectProperty(ErrorString* errorString,
-                                        v8::Local<v8::Object> object,
-                                        v8::Local<v8::Name> key,
-                                        const String16& groupName,
-                                        bool forceValueType,
-                                        bool generatePreview) const {
+Response InjectedScript::wrapObjectProperty(v8::Local<v8::Object> object,
+                                            v8::Local<v8::Name> key,
+                                            const String16& groupName,
+                                            bool forceValueType,
+                                            bool generatePreview) const {
   v8::Local<v8::Value> property;
   v8::Local<v8::Context> context = m_context->context();
-  if (hasInternalError(errorString,
-                       !object->Get(context, key).ToLocal(&property)))
-    return false;
+  if (!object->Get(context, key).ToLocal(&property))
+    return Response::InternalError();
   v8::Local<v8::Value> wrappedProperty;
-  if (!wrapValue(errorString, property, groupName, forceValueType,
-                 generatePreview)
-           .ToLocal(&wrappedProperty))
-    return false;
+  Response response = wrapValue(property, groupName, forceValueType,
+                                generatePreview, wrappedProperty);
+  if (!response.isSuccess()) return response;
   v8::Maybe<bool> success =
       createDataProperty(context, object, key, wrappedProperty);
-  if (hasInternalError(errorString, success.IsNothing() || !success.FromJust()))
-    return false;
-  return true;
+  if (success.IsNothing() || !success.FromJust())
+    return Response::InternalError();
+  return Response::OK();
 }
 
-bool InjectedScript::wrapPropertyInArray(ErrorString* errorString,
-                                         v8::Local<v8::Array> array,
-                                         v8::Local<v8::String> property,
-                                         const String16& groupName,
-                                         bool forceValueType,
-                                         bool generatePreview) const {
+Response InjectedScript::wrapPropertyInArray(v8::Local<v8::Array> array,
+                                             v8::Local<v8::String> property,
+                                             const String16& groupName,
+                                             bool forceValueType,
+                                             bool generatePreview) const {
   V8FunctionCall function(m_context->inspector(), m_context->context(),
                           v8Value(), "wrapPropertyInArray");
   function.appendArgument(array);
   function.appendArgument(property);
   function.appendArgument(groupName);
   function.appendArgument(forceValueType);
   function.appendArgument(generatePreview);
   bool hadException = false;
   function.call(hadException);
-  return !hasInternalError(errorString, hadException);
+  return hadException ? Response::InternalError() : Response::OK();
 }
 
-bool InjectedScript::wrapObjectsInArray(ErrorString* errorString,
-                                        v8::Local<v8::Array> array,
-                                        const String16& groupName,
-                                        bool forceValueType,
-                                        bool generatePreview) const {
-  V8FunctionCall function(m_context->inspector(), m_context->context(),
-                          v8Value(), "wrapObjectsInArray");
-  function.appendArgument(array);
-  function.appendArgument(groupName);
-  function.appendArgument(forceValueType);
-  function.appendArgument(generatePreview);
-  bool hadException = false;
-  function.call(hadException);
-  return !hasInternalError(errorString, hadException);
-}
-
-v8::MaybeLocal<v8::Value> InjectedScript::wrapValue(
-    ErrorString* errorString, v8::Local<v8::Value> value,
-    const String16& groupName, bool forceValueType,
-    bool generatePreview) const {
+Response InjectedScript::wrapValue(v8::Local<v8::Value> value,
+                                   const String16& groupName,
+                                   bool forceValueType, bool generatePreview,
+                                   v8::Local<v8::Value>& result) const {
+  result = v8::Local<v8::Value>();

[dgozman, 2016/11/02 19:53:59]

remove

[kozy, 2016/11/02 22:45:13]

Done.

   V8FunctionCall function(m_context->inspector(), m_context->context(),
                           v8Value(), "wrapObject");
   function.appendArgument(value);
   function.appendArgument(groupName);
   function.appendArgument(forceValueType);
   function.appendArgument(generatePreview);
   bool hadException = false;
   v8::Local<v8::Value> r = function.call(hadException);

[dgozman, 2016/11/02 19:53:59]

*result =

[kozy, 2016/11/02 22:45:13]

Done.

-  if (hasInternalError(errorString, hadException || r.IsEmpty()))
-    return v8::MaybeLocal<v8::Value>();
-  return r;
+  if (hadException || r.IsEmpty()) return Response::InternalError();
+  result = r;
+  return Response::OK();
 }
 
 std::unique_ptr<protocol::Runtime::RemoteObject> InjectedScript::wrapTable(
     v8::Local<v8::Value> table, v8::Local<v8::Value> columns) const {
   v8::HandleScope handles(m_context->isolate());
   v8::Local<v8::Context> context = m_context->context();
   V8FunctionCall function(m_context->inspector(), context, v8Value(),
                           "wrapTable");
   function.appendArgument(table);
   if (columns.IsEmpty())
     function.appendArgument(false);
   else
     function.appendArgument(columns);
   bool hadException = false;
   v8::Local<v8::Value> r = function.call(hadException);
   if (hadException || r.IsEmpty()) return nullptr;
-  protocol::ErrorString errorString;
-  std::unique_ptr<protocol::Value> protocolValue =
-      toProtocolValue(&errorString, context, r);
-  if (!protocolValue) return nullptr;
+  std::unique_ptr<protocol::Value> protocolValue;
+  Response response = toProtocolValue(context, r, 1000, protocolValue);
+  if (!response.isSuccess()) return nullptr;
   protocol::ErrorSupport errors;
   return protocol::Runtime::RemoteObject::parse(protocolValue.get(), &errors);
 }
 
-bool InjectedScript::findObject(ErrorString* errorString,
-                                const RemoteObjectId& objectId,
-                                v8::Local<v8::Value>* outObject) const {
+Response InjectedScript::findObject(const RemoteObjectId& objectId,
+                                    v8::Local<v8::Value>* outObject) const {
   *outObject = m_native->objectForId(objectId.id());
   if (outObject->IsEmpty())
-    *errorString = "Could not find object with given id";
-  return !outObject->IsEmpty();
+    return Response::Error("Could not find object with given id");
+  return Response::OK();
 }
 
 String16 InjectedScript::objectGroupName(const RemoteObjectId& objectId) const {
   return m_native->groupName(objectId.id());
 }
 
 void InjectedScript::releaseObjectGroup(const String16& objectGroup) {
   m_native->releaseObjectGroup(objectGroup);
   if (objectGroup == "console") m_lastEvaluationResult.Reset();
 }
@@ skipping 11 matching lines @@
 v8::Local<v8::Value> InjectedScript::v8Value() const {
   return m_value.Get(m_context->isolate());
 }
 
 v8::Local<v8::Value> InjectedScript::lastEvaluationResult() const {
   if (m_lastEvaluationResult.IsEmpty())
     return v8::Undefined(m_context->isolate());
   return m_lastEvaluationResult.Get(m_context->isolate());
 }
 
-v8::MaybeLocal<v8::Value> InjectedScript::resolveCallArgument(
-    ErrorString* errorString, protocol::Runtime::CallArgument* callArgument) {
+Response InjectedScript::resolveCallArgument(
+    protocol::Runtime::CallArgument* callArgument,
+    v8::Local<v8::Value>& result) {

[dgozman, 2016/11/02 19:54:00]

v8::Local<>*

[kozy, 2016/11/02 22:45:12]

Done.

+  result = v8::Local<v8::Value>();
   if (callArgument->hasObjectId()) {
-    std::unique_ptr<RemoteObjectId> remoteObjectId =
-        RemoteObjectId::parse(errorString, callArgument->getObjectId(""));
-    if (!remoteObjectId) return v8::MaybeLocal<v8::Value>();
-    if (remoteObjectId->contextId() != m_context->contextId()) {
-      *errorString =
+    std::unique_ptr<RemoteObjectId> remoteObjectId;
+    Response response =
+        RemoteObjectId::parse(callArgument->getObjectId(""), remoteObjectId);
+    if (!response.isSuccess()) return response;
+    if (remoteObjectId->contextId() != m_context->contextId())
+      return Response::Error(
           "Argument should belong to the same JavaScript world as target "
-          "object";
-      return v8::MaybeLocal<v8::Value>();
-    }
+          "object");
     v8::Local<v8::Value> object;
-    if (!findObject(errorString, *remoteObjectId, &object))
-      return v8::MaybeLocal<v8::Value>();
-    return object;
+    response = findObject(*remoteObjectId, &object);

[dgozman, 2016/11/02 19:53:59]

&object -> result

[kozy, 2016/11/02 22:45:13]

Done.

+    if (!response.isSuccess()) return response;
+    result = object;
+    return Response::OK();
   }
   if (callArgument->hasValue() || callArgument->hasUnserializableValue()) {
     String16 value =
         callArgument->hasValue()
             ? callArgument->getValue(nullptr)->toJSONString()
             : "Number(\"" + callArgument->getUnserializableValue("") + "\")";
     v8::Local<v8::Value> object;
     if (!m_context->inspector()
              ->compileAndRunInternalScript(
                  m_context->context(), toV8String(m_context->isolate(), value))
              .ToLocal(&object)) {

[dgozman, 2016/11/02 19:53:59]

.ToLocal(result)

[kozy, 2016/11/02 22:45:13]

Done.

-      *errorString = "Couldn't parse value object in call argument";
-      return v8::MaybeLocal<v8::Value>();
+      return Response::Error("Couldn't parse value object in call argument");
     }
-    return object;
+    result = object;
+    return Response::OK();
   }
-  return v8::Undefined(m_context->isolate());
+  result = v8::Undefined(m_context->isolate());
+  return Response::OK();
 }
 
-std::unique_ptr<protocol::Runtime::ExceptionDetails>
-InjectedScript::createExceptionDetails(ErrorString* errorString,
-                                       const v8::TryCatch& tryCatch,
-                                       const String16& objectGroup,
-                                       bool generatePreview) {
-  if (!tryCatch.HasCaught()) return nullptr;
+Response InjectedScript::createExceptionDetails(
+    const v8::TryCatch& tryCatch, const String16& objectGroup,
+    bool generatePreview, Maybe<protocol::Runtime::ExceptionDetails>& result) {
+  if (!tryCatch.HasCaught()) return Response::InternalError();
   v8::Local<v8::Message> message = tryCatch.Message();
   v8::Local<v8::Value> exception = tryCatch.Exception();
   String16 messageText =
       message.IsEmpty() ? String16() : toProtocolString(message->Get());
   std::unique_ptr<protocol::Runtime::ExceptionDetails> exceptionDetails =

[dgozman, 2016/11/02 19:53:59]

*result = ...

[kozy, 2016/11/02 22:45:12]

I preferred to store it in separate variable since using
unique_ptr<ExceptionDetails> is easier then using Maybe.

       protocol::Runtime::ExceptionDetails::create()
           .setExceptionId(m_context->inspector()->nextExceptionId())
           .setText(exception.IsEmpty() ? messageText : String16("Uncaught"))
           .setLineNumber(
               message.IsEmpty()
                   ? 0
                   : message->GetLineNumber(m_context->context()).FromMaybe(1) -
                         1)
           .setColumnNumber(
               message.IsEmpty()
                   ? 0
                   : message->GetStartColumn(m_context->context()).FromMaybe(0))
           .build();
   if (!message.IsEmpty()) {
     exceptionDetails->setScriptId(String16::fromInteger(
         static_cast<int>(message->GetScriptOrigin().ScriptID()->Value())));
     v8::Local<v8::StackTrace> stackTrace = message->GetStackTrace();
     if (!stackTrace.IsEmpty() && stackTrace->GetFrameCount() > 0)
       exceptionDetails->setStackTrace(m_context->inspector()
                                           ->debugger()
                                           ->createStackTrace(stackTrace)
                                           ->buildInspectorObjectImpl());
   }
   if (!exception.IsEmpty()) {
-    std::unique_ptr<protocol::Runtime::RemoteObject> wrapped = wrapObject(
-        errorString, exception, objectGroup, false /* forceValueType */,
-        generatePreview && !exception->IsNativeError());
-    if (!wrapped) return nullptr;
+    std::unique_ptr<protocol::Runtime::RemoteObject> wrapped;
+    Response response =
+        wrapObject(exception, objectGroup, false /* forceValueType */,
+                   generatePreview && !exception->IsNativeError(), wrapped);
+    if (!response.isSuccess()) return response;
     exceptionDetails->setException(std::move(wrapped));
   }
-  return exceptionDetails;
+  result = std::move(exceptionDetails);
+  return Response::OK();
 }
 
-void InjectedScript::wrapEvaluateResult(
-    ErrorString* errorString, v8::MaybeLocal<v8::Value> maybeResultValue,
-    const v8::TryCatch& tryCatch, const String16& objectGroup,
-    bool returnByValue, bool generatePreview,
+Response InjectedScript::wrapEvaluateResult(
+    v8::MaybeLocal<v8::Value> maybeResultValue, const v8::TryCatch& tryCatch,
+    const String16& objectGroup, bool returnByValue, bool generatePreview,
     std::unique_ptr<protocol::Runtime::RemoteObject>* result,
     Maybe<protocol::Runtime::ExceptionDetails>* exceptionDetails) {
   v8::Local<v8::Value> resultValue;
   if (!tryCatch.HasCaught()) {
-    if (hasInternalError(errorString, !maybeResultValue.ToLocal(&resultValue)))
-      return;
-    std::unique_ptr<RemoteObject> remoteObject = wrapObject(
-        errorString, resultValue, objectGroup, returnByValue, generatePreview);
-    if (!remoteObject) return;
+    if (!maybeResultValue.ToLocal(&resultValue))
+      return Response::InternalError();
+    std::unique_ptr<RemoteObject> remoteObject;
+    Response response = wrapObject(resultValue, objectGroup, returnByValue,
+                                   generatePreview, remoteObject);

[dgozman, 2016/11/02 19:53:59]

remoteObject -> result

[kozy, 2016/11/02 22:45:12]

Done.

+    if (!response.isSuccess()) return response;
     if (objectGroup == "console")
       m_lastEvaluationResult.Reset(m_context->isolate(), resultValue);
     *result = std::move(remoteObject);
   } else {
     v8::Local<v8::Value> exception = tryCatch.Exception();
-    std::unique_ptr<RemoteObject> remoteObject =
-        wrapObject(errorString, exception, objectGroup, false,
-                   generatePreview && !exception->IsNativeError());
-    if (!remoteObject) return;
+    std::unique_ptr<RemoteObject> remoteObject;
+    Response response = wrapObject(
+        exception, objectGroup, false,
+        generatePreview && !exception->IsNativeError(), remoteObject);

[dgozman, 2016/11/02 19:53:59]

ditto

[kozy, 2016/11/02 22:45:12]

Done.

+    if (!response.isSuccess()) return response;
     // We send exception in result for compatibility reasons, even though it's
     // accessible through exceptionDetails.exception.
     *result = std::move(remoteObject);
-    *exceptionDetails = createExceptionDetails(errorString, tryCatch,
-                                               objectGroup, generatePreview);
+    response = createExceptionDetails(tryCatch, objectGroup, generatePreview,
+                                      *exceptionDetails);
+    if (!response.isSuccess()) return response;
   }
+  return Response::OK();
 }
 
 v8::Local<v8::Object> InjectedScript::commandLineAPI() {
   if (m_commandLineAPI.IsEmpty())
     m_commandLineAPI.Reset(m_context->isolate(),
                            V8Console::createCommandLineAPI(m_context));
   return m_commandLineAPI.Get(m_context->isolate());
 }
 
-InjectedScript::Scope::Scope(ErrorString* errorString,
-                             V8InspectorImpl* inspector, int contextGroupId)
-    : m_errorString(errorString),
-      m_inspector(inspector),
+InjectedScript::Scope::Scope(V8InspectorImpl* inspector, int contextGroupId)
+    : m_inspector(inspector),
       m_contextGroupId(contextGroupId),
       m_injectedScript(nullptr),
       m_handleScope(inspector->isolate()),
       m_tryCatch(inspector->isolate()),
       m_ignoreExceptionsAndMuteConsole(false),
       m_previousPauseOnExceptionsState(v8::DebugInterface::NoBreakOnException),
       m_userGesture(false) {}
 
-bool InjectedScript::Scope::initialize() {
+Response InjectedScript::Scope::initialize() {
   cleanup();
   // TODO(dgozman): what if we reattach to the same context group during
   // evaluate? Introduce a session id?
   V8InspectorSessionImpl* session =
       m_inspector->sessionForContextGroup(m_contextGroupId);
-  if (!session) {
-    *m_errorString = "Internal error";
-    return false;
-  }
-  findInjectedScript(session);
-  if (!m_injectedScript) return false;
+  if (!session) return Response::InternalError();
+  Response response = findInjectedScript(session);
+  if (!response.isSuccess()) return response;
   m_context = m_injectedScript->context()->context();
   m_context->Enter();
-  return true;
+  return Response::OK();
 }
 
-bool InjectedScript::Scope::installCommandLineAPI() {
+void InjectedScript::Scope::installCommandLineAPI() {
   DCHECK(m_injectedScript && !m_context.IsEmpty() &&
          !m_commandLineAPIScope.get());
   m_commandLineAPIScope.reset(new V8Console::CommandLineAPIScope(
       m_context, m_injectedScript->commandLineAPI(), m_context->Global()));
-  return true;
 }
 
 void InjectedScript::Scope::ignoreExceptionsAndMuteConsole() {
   DCHECK(!m_ignoreExceptionsAndMuteConsole);
   m_ignoreExceptionsAndMuteConsole = true;
   m_inspector->client()->muteMetrics(m_contextGroupId);
   m_inspector->muteExceptions(m_contextGroupId);
   m_previousPauseOnExceptionsState =
       setPauseOnExceptionsState(v8::DebugInterface::NoBreakOnException);
 }
@@ skipping 26 matching lines @@
 InjectedScript::Scope::~Scope() {
   if (m_ignoreExceptionsAndMuteConsole) {
     setPauseOnExceptionsState(m_previousPauseOnExceptionsState);
     m_inspector->client()->unmuteMetrics(m_contextGroupId);
     m_inspector->unmuteExceptions(m_contextGroupId);
   }
   if (m_userGesture) m_inspector->client()->endUserGesture();
   cleanup();
 }
 
-InjectedScript::ContextScope::ContextScope(ErrorString* errorString,
-                                           V8InspectorImpl* inspector,
+InjectedScript::ContextScope::ContextScope(V8InspectorImpl* inspector,
                                            int contextGroupId,
                                            int executionContextId)
-    : InjectedScript::Scope(errorString, inspector, contextGroupId),
+    : InjectedScript::Scope(inspector, contextGroupId),
       m_executionContextId(executionContextId) {}
 
 InjectedScript::ContextScope::~ContextScope() {}
 
-void InjectedScript::ContextScope::findInjectedScript(
+Response InjectedScript::ContextScope::findInjectedScript(
     V8InspectorSessionImpl* session) {
-  m_injectedScript =
-      session->findInjectedScript(m_errorString, m_executionContextId);
+  return session->findInjectedScript(m_executionContextId, m_injectedScript);
 }
 
-InjectedScript::ObjectScope::ObjectScope(ErrorString* errorString,
-                                         V8InspectorImpl* inspector,
+InjectedScript::ObjectScope::ObjectScope(V8InspectorImpl* inspector,
                                          int contextGroupId,
                                          const String16& remoteObjectId)
-    : InjectedScript::Scope(errorString, inspector, contextGroupId),
+    : InjectedScript::Scope(inspector, contextGroupId),
       m_remoteObjectId(remoteObjectId) {}
 
 InjectedScript::ObjectScope::~ObjectScope() {}
 
-void InjectedScript::ObjectScope::findInjectedScript(
+Response InjectedScript::ObjectScope::findInjectedScript(
     V8InspectorSessionImpl* session) {
-  std::unique_ptr<RemoteObjectId> remoteId =
-      RemoteObjectId::parse(m_errorString, m_remoteObjectId);
-  if (!remoteId) return;
-  InjectedScript* injectedScript =
-      session->findInjectedScript(m_errorString, remoteId.get());
-  if (!injectedScript) return;
+  std::unique_ptr<RemoteObjectId> remoteId;
+  Response response = RemoteObjectId::parse(m_remoteObjectId, remoteId);
+  if (!response.isSuccess()) return response;
+  InjectedScript* injectedScript = nullptr;
+  response = session->findInjectedScript(remoteId.get(), injectedScript);
+  if (!response.isSuccess()) return response;
   m_objectGroupName = injectedScript->objectGroupName(*remoteId);
-  if (!injectedScript->findObject(m_errorString, *remoteId, &m_object)) return;
+  response = injectedScript->findObject(*remoteId, &m_object);
+  if (!response.isSuccess()) return response;
   m_injectedScript = injectedScript;
+  return Response::OK();
 }
 
-InjectedScript::CallFrameScope::CallFrameScope(ErrorString* errorString,
-                                               V8InspectorImpl* inspector,
+InjectedScript::CallFrameScope::CallFrameScope(V8InspectorImpl* inspector,
                                                int contextGroupId,
                                                const String16& remoteObjectId)
-    : InjectedScript::Scope(errorString, inspector, contextGroupId),
+    : InjectedScript::Scope(inspector, contextGroupId),
       m_remoteCallFrameId(remoteObjectId) {}
 
 InjectedScript::CallFrameScope::~CallFrameScope() {}
 
-void InjectedScript::CallFrameScope::findInjectedScript(
+Response InjectedScript::CallFrameScope::findInjectedScript(
     V8InspectorSessionImpl* session) {
-  std::unique_ptr<RemoteCallFrameId> remoteId =
-      RemoteCallFrameId::parse(m_errorString, m_remoteCallFrameId);
-  if (!remoteId) return;
+  std::unique_ptr<RemoteCallFrameId> remoteId;
+  Response response = RemoteCallFrameId::parse(m_remoteCallFrameId, remoteId);
+  if (!response.isSuccess()) return response;
   m_frameOrdinal = static_cast<size_t>(remoteId->frameOrdinal());
-  m_injectedScript = session->findInjectedScript(m_errorString, remoteId.get());
+  return session->findInjectedScript(remoteId.get(), m_injectedScript);
 }
 
 }  // namespace v8_inspector