Is Send to Kindle for Google Chrome™ safe?

onSendToKindle: function () {    chrome.runtime.sendMessage({        action: "metrics-add-counter",        data: {            metricsName: MetricsNames["pop-main-send-click"]        }    });    // Check auth status before send    $S2K.onCheckAuth(false, function (isAuthed) {        if (isAuthed) {            chrome.runtime.sendMessage({"action": "extract", "preview": false, "selected": false}, function () {                // Close window.                $S2K.onClose();            });        } else {            // Change to un authed UI            $S2K.changeUIWithId($S2K.ID_UN_AUTHED_DIV, false);        }    });},

extractContent: function (preview, selected, shortcut) {    chrome.tabs.query({active: true, lastFocusedWindow: true}, function (queryResults) {        let tab = queryResults[0];        if (tab && (tab.url.indexOf("chrome://") === -1) && (tab.url.indexOf("chrome-extension://") === -1)) {            // Execute background logic.            chrome.scripting.executeScript({                target: {tabId: tab.id}, func: function (preview, selected, shortcut) {                    globalThis.launchExtraction(preview, selected, shortcut);                }, args: [preview, selected, shortcut]            });        }    });},

const launchExtraction = function (previewOnly, selectedOnly, usedShortcut) {    // Load extension state for current window.    const state = getState();    if (state.inProgress) {        return;    }    // Somehow, if we're trying to extract content before the    // content script has been fully injected and the state transition    // between the SW and the content script has finished, try again in 250ms    if (!state.isInjected) {        setTimeout(launchExtraction, 250);        return;    }    // Set desired action in state.    state.isPreviewOnly = previewOnly || false;    state.isSelectedOnly = selectedOnly || false;    state.isShortcut = usedShortcut || false;    // Initialize progress information.    state.statusMessage = state.statusMessage || new StatusMessage("status");    // Reset progress state    state.resetProgress();    // Register cancel event    state.statusMessage.registerEvent("cancelProgress", function () {        // Stop monitoring unload action        removeUnloadListener(preventFromUnload);        state.cancelProgress = true;        chrome.runtime.sendMessage({            action: "set-cancel-sending",            data: {                cancel: true            }        });    });    // Perform action only, if the content has a body and it is not already a preview.        if (state.stateDocument.body && !state.stateDocument.location.pathname.match(/^\/gp\/sendtokindle\/(reader|setup)/i)) {        // Record metrics        chrome.runtime.sendMessage({            action: "metrics-add-counter",            data: {                metricsName: MetricsNames["extract-count"]            }        });        chrome.runtime.sendMessage({            action: "metrics-start-timer",            data: {                metricsName: MetricsNames["extract-time"]            }        });        // Use `report-low-rating` metrics to record all url when starting extraction, rating as "999"        chrome.runtime.sendMessage({            action: "report-low-rating",            data: {                rating: "999",                url: state.stateDocument.URL || ""            }        });        // Prevent from unload page        addUnloadListener(preventFromUnload);        // Show analyzing alert        state.statusMessage.showAlert("progress", "analyzing");        // Release UI thread for drawing the spinner.        setTimeout(function () {            // Run extraction process, if necessarily.            if (!state.content) {                // New logic (call web-extraction) will be executed first                let newExtractor = new S2KWebExtractor();                let task = {                    timeoutTimeInMillis: Date.now() + EXTRACTION_TIMEOUT_MILLIS,                    isTimedOut: function () {                        return Date.now() > this.timeoutTimeInMillis;                    }                };                task.progress = launchProgress.bind(task);                // This `backup` is old logic, it's a backup logic for now. If the web-extraction failed, will trigger this                task.backup = function () {                    let extractor = createExtractor(state);                    extractor.extract(task);                };                // Execute new extract logic                newExtractor.extract(task);            } else {                launchProgress({"success": true, "data": state.content, "value": 1.0});            }        }, 0);    }};

} else if (message.action === "report-low-rating") {    reportLowRating(message.data.rating, message.data.url).then(function () {        if (sendResponse ) {            sendResponse();        }    });} else if (message.action === "extract-epub") {

async function reportLowRating(rating, url) {    let path = "/extension/recordLowRatingUrl";    let res = await ajax({        type: "POST",        path: path,        dataType: "json",        isJSONContentType: true,        isCsrfRequired: true,        cache: false,        timeout: 10000,        data: {            "rating": rating,            "url": url        },    });    return res.success;}