Debugger.setVariableValue

{
  "name": "setVariableValue",
  "parameters": [
    {
      "name": "scopeNumber",
      "type": "integer",
      "description": "0-based number of scope as was listed in scope chain. Only 'local', 'closure' and 'catch' scope types are allowed. Other scopes could be manipulated manually."
    },
    {
      "name": "variableName",
      "type": "string",
      "description": "Variable name."
    },
    {
      "name": "newValue",
      "$ref": "Runtime.CallArgument",
      "description": "New variable value."
    },
    {
      "name": "callFrameId",
      "$ref": "CallFrameId",
      "description": "Id of callframe that holds variable."
    }
  ],
  "description": "Changes value of variable in a callframe. Object-based scopes are not supported and must be mutated manually."
}