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

src/inspector/js_protocol.json

Index: src/inspector/js_protocol.json
diff --git a/src/inspector/js_protocol.json b/src/inspector/js_protocol.json
index 8ef1c8c8f1f6992020d005faf2504ab0ce74f87e..8b08b0bda49b15093bee5a7896d15cc6205da653 100644
--- a/src/inspector/js_protocol.json
+++ b/src/inspector/js_protocol.json
@@ -635,7 +635,8 @@
                     { "name": "includeCommandLineAPI", "type": "boolean", "optional": true, "description": "Specifies whether command line API should be available to the evaluated expression, defaults to false." },
                     { "name": "silent", "type": "boolean", "optional": true, "description": "In silent mode exceptions thrown during evaluation are not reported and do not pause execution. Overrides <code>setPauseOnException</code> state." },
                     { "name": "returnByValue", "type": "boolean", "optional": true, "description": "Whether the result is expected to be a JSON object that should be sent by value." },
-                    { "name": "generatePreview", "type": "boolean", "optional": true, "experimental": true, "description": "Whether preview should be generated for the result." }
+                    { "name": "generatePreview", "type": "boolean", "optional": true, "experimental": true, "description": "Whether preview should be generated for the result." },
+                    { "name": "throwOnSideEffect", "type": "boolean", "optional": true, "experimental": true, "description": "Whether to throw an exception if side effect cannot be ruled out during evaluation." }
                 ],
                 "returns": [
                     { "name": "result", "$ref": "Runtime.RemoteObject", "description": "Object wrapper for the evaluation result." },