Add chrome.offscreen to chrome extension externs
@@ -5704,6 +5704,55 @@ chrome.mediaGalleries.ScanProgressEvent = function() {};
chrome.mediaGalleries.onScanProgress;
+/**
+ * @const
+ * @see https://developer.chrome.com/docs/extensions/reference/offscreen/
+ */
+chrome.offscreen = {};
+
+/**
+ * @typedef {{
+ * justification: string,
+ * reasons: !Array<!chrome.offscreen.Reason>,
+ * url: string,
+ * }}
+ * @see https://developer.chrome.com/docs/extensions/reference/offscreen/#type-CreateParameters
+ */
+chrome.offscreen.CreateParameters;
+
+/**
+ * @enum {string}
+ * @see https://developer.chrome.com/docs/extensions/reference/offscreen/#type-Reason
+ */
+chrome.offscreen.Reason = {
+ TESTING: '',
+ AUDIO_PLAYBACK: '',
+ IFRAME_SCRIPTING: '',
+ DOM_SCRAPING: '',
+ BLOBS: '',
+ DOM_PARSER: '',
+ USER_MEDIA: '',
+ DISPLAY_MEDIA: '',
+ WEB_RTC: '',
+ CLIPBOARD: '',
+};
+
+/**
+ * @param {function(): void=} opt_callback
+ * @return {undefined}
+ * @see https://developer.chrome.com/docs/extensions/reference/offscreen/#method-closeDocument
+ */
+chrome.offscreen.closeDocument = function(opt_callback) {};
+
+/**
+ * @param {!chrome.offscreen.CreateParameters} parameters The parameters
+ * describing the offscreen document to create.
+ * @param {function(): void=} opt_callback
+ * @return {undefined}
+ * @see https://developer.chrome.com/docs/extensions/reference/offscreen/#method-createDocument
+ */
+chrome.offscreen.createDocument = function(parameters, opt_callback) {};
+
/**
* @const
* @see https://developer.chrome.com/extensions/pageCapture.html
