Launch webstore widget app when unsupported printer is plugged in

components/chrome_apps/webstore_widget/app/background.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// TODO(tbarzic): Implement this.
+/** @const {number} */
+var APP_WINDOW_WIDTH = 735;
+
+/** @const {number} */
+var APP_WINDOW_HEIGHT = 530;
+
+chrome.webstoreWidgetPrivate.onShowWidget.addListener(function(options) {
+  if (!options || options.type != 'PRINTER_PROVIDER' || !options.usbId) {
+    console.error('Invalid widget options.');
+    return;
+  }
+
+  chrome.app.window.create('app/main.html', {
+    id: JSON.stringify(options),
+    frame: 'none',
+    innerBounds: {width: APP_WINDOW_WIDTH, height: APP_WINDOW_HEIGHT},
+    resizable: false
+  }, function(createdWindow) {
+    createdWindow.contentWindow.params = {
+      filter: {
+        'printer_provider_vendor_id': options.usbId.vendorId,
+        'printer_provider_product_id': options.usbId.productId
+     },
+     webstoreUrl: null
+    };
+  });
+});