[debugger] expose side-effect free evaluate to inspector.

src/inspector/v8-debugger-agent-impl.cc

Index: src/inspector/v8-debugger-agent-impl.cc
diff --git a/src/inspector/v8-debugger-agent-impl.cc b/src/inspector/v8-debugger-agent-impl.cc
index 1ad7389da62ffe74e35a8accd28052f2a17db435..7de46a1787818170d3e91cd0902a0b2f977ecfcf 100644
--- a/src/inspector/v8-debugger-agent-impl.cc
+++ b/src/inspector/v8-debugger-agent-impl.cc
@@ -703,7 +703,7 @@ Response V8DebuggerAgentImpl::evaluateOnCallFrame(
     const String16& callFrameId, const String16& expression,
     Maybe<String16> objectGroup, Maybe<bool> includeCommandLineAPI,
     Maybe<bool> silent, Maybe<bool> returnByValue, Maybe<bool> generatePreview,
-    std::unique_ptr<RemoteObject>* result,
+    Maybe<bool> throwOnSideEffect, std::unique_ptr<RemoteObject>* result,
     Maybe<protocol::Runtime::ExceptionDetails>* exceptionDetails) {
   if (!isPaused()) return Response::Error(kDebuggerNotPaused);
   InjectedScript::CallFrameScope scope(m_inspector, m_session->contextGroupId(),
@@ -718,7 +718,8 @@ Response V8DebuggerAgentImpl::evaluateOnCallFrame(
 
   v8::MaybeLocal<v8::Value> maybeResultValue =
       m_pausedCallFrames[scope.frameOrdinal()]->evaluate(
-          toV8String(m_isolate, expression));
+          toV8String(m_isolate, expression),
+          throwOnSideEffect.fromMaybe(false));
 
   // Re-initialize after running client's code, as it could have destroyed
   // context or session.