Print Preview WebUI tests: Use const instead of let where possible.

CL produced with ESLint --fix and clang-format.

This is in preparation for turning on the 'prefer-const' ESLint rule for that
folder.

Bug: 72003
Change-Id: I94a6f0ae63da907e552c659325de600b6b3733c8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1885553
Auto-Submit: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710372}

chrome/test/data/webui/print_preview/advanced_dialog_test.js

@@ -22,10 +22,10 @@ cr.define('advanced_dialog_test', function() {
     let destination = null;
 
     /** @type {string} */
-    let printerId = 'FooDevice';
+    const printerId = 'FooDevice';
 
     /** @type {string} */
-    let printerName = 'FooName';
+    const printerName = 'FooName';
 
     /** @override */
     setup(function() {

chrome/test/data/webui/print_preview/custom_margins_test.js

@@ -89,7 +89,7 @@ cr.define('custom_margins_test', function() {
       // Wait for the control elements to be created before updating the state.
       container.measurementSystem = measurementSystem;
       document.body.appendChild(container);
-      let controlsAdded = test_util.eventToPromise('dom-change', container);
+      const controlsAdded = test_util.eventToPromise('dom-change', container);
       return controlsAdded.then(() => {
         // 8.5 x 11, in pixels
         const controls = getControls();
@@ -275,7 +275,7 @@ cr.define('custom_margins_test', function() {
               assertEquals('0', window.getComputedStyle(control).opacity);
             });
 
-            let onTransitionEnd = getAllTransitions(controls);
+            const onTransitionEnd = getAllTransitions(controls);
             // Controls become visible when margin type CUSTOM is selected.
             model.set(
                 'settings.margins.value', print_preview.MarginsType.CUSTOM);
@@ -309,7 +309,7 @@ cr.define('custom_margins_test', function() {
               assertEquals(defaultMarginPts, control.getPositionInPts());
             });
 
-            let onTransitionEnd = getAllTransitions(controls);
+            const onTransitionEnd = getAllTransitions(controls);
 
             // Disappears when preview is loading or an error message is shown.
             // Check that all the controls also disappear.

chrome/test/data/webui/print_preview/destination_dialog_test.js

@@ -28,7 +28,7 @@ cr.define('destination_dialog_test', function() {
     let destinations = [];
 
     /** @type {!Array<!print_preview.LocalDestinationInfo>} */
-    let localDestinations = [];
+    const localDestinations = [];
 
     /** @type {!Array<!print_preview.RecentDestination>} */
     let recentDestinations = [];

chrome/test/data/webui/print_preview/destination_item_test.js

@@ -53,7 +53,7 @@ cr.define('destination_item_test', function() {
     // the destination is stale.
     test(assert(TestNames.Offline), function() {
       const now = new Date();
-      let twoMonthsAgo = new Date(now.getTime());
+      const twoMonthsAgo = new Date(now.getTime());
       let month = twoMonthsAgo.getMonth() - 2;
       if (month < 0) {
         month = month + 12;

chrome/test/data/webui/print_preview/destination_settings_test.js

@@ -54,7 +54,7 @@ cr.define('destination_settings_test', function() {
       // Stub out native layer and cloud print interface.
       nativeLayer = new print_preview.NativeLayerStub();
       print_preview.NativeLayer.setInstance(nativeLayer);
-      let localDestinations = [];
+      const localDestinations = [];
       destinations = print_preview_test_utils.getDestinations(
           nativeLayer, localDestinations);
       nativeLayer.setLocalDestinations(localDestinations);
@@ -197,7 +197,7 @@ cr.define('destination_settings_test', function() {
      *     destinations in the dropdown.
      */
     function assertDropdownItems(expectedDestinations) {
-      let options =
+      const options =
           destinationSettings.$.destinationSelect.shadowRoot.querySelectorAll(
               'option:not([hidden])');
       assertEquals(expectedDestinations.length + 1, options.length);

chrome/test/data/webui/print_preview/model_settings_availability_test.js

@@ -245,7 +245,7 @@ cr.define('model_settings_availability_test', function() {
       assertTrue(model.settings.mediaSize.available);
 
       // Remove capability.
-      let capabilities =
+      const capabilities =
           print_preview_test_utils.getCddTemplate(model.destination.id)
               .capabilities;
       delete capabilities.printer.media_size;

chrome/test/data/webui/print_preview/model_test.js

@@ -90,7 +90,8 @@ cr.define('model_test', function() {
        *     reset to its default value.
        */
       const testStickySetting = function(setting, field) {
-        let promise = test_util.eventToPromise('sticky-setting-changed', model);
+        const promise =
+            test_util.eventToPromise('sticky-setting-changed', model);
         model.setSetting(setting, stickySettingsChange[field]);
         settingsSet.push(field);
         return promise.then(
@@ -99,18 +100,19 @@ cr.define('model_test', function() {
              * @return {!Promise} Promise that resolves when setting is reset.
              */
             function(e) {
-              let settings = JSON.parse(e.detail);
+              const settings = JSON.parse(e.detail);
               Object.keys(stickySettingsDefault).forEach(settingName => {
-                let set = settingsSet.includes(settingName);
+                const set = settingsSet.includes(settingName);
                 assertEquals(set, settings[settingName] !== undefined);
                 if (set) {
-                  let toCompare = settingName == field ? stickySettingsChange :
-                                                         stickySettingsDefault;
+                  const toCompare = settingName == field ?
+                      stickySettingsChange :
+                      stickySettingsDefault;
                   assertDeepEquals(
                       toCompare[settingName], settings[settingName]);
                 }
               });
-              let restorePromise =
+              const restorePromise =
                   test_util.eventToPromise('sticky-setting-changed', model);
               model.setSetting(setting, stickySettingsDefault[field]);
               return restorePromise;

chrome/test/data/webui/print_preview/print_button_test.js

@@ -33,7 +33,7 @@ cr.define('print_button_test', function() {
       print_preview.NativeLayer.setInstance(nativeLayer);
       PolymerTest.clearBody();
       nativeLayer.setInitialSettings(initialSettings);
-      let localDestinationInfos = [
+      const localDestinationInfos = [
         {printerName: 'FooName', deviceName: 'FooDevice'},
       ];
       nativeLayer.setLocalDestinations(localDestinationInfos);

chrome/test/data/webui/print_preview/print_preview_test_utils.js

@@ -257,7 +257,7 @@ cr.define('print_preview_test_utils', function() {
    * @return {!Array<!print_preview.Destination>}
    */
   function getDestinations(nativeLayer, localDestinations) {
-    let destinations = [];
+    const destinations = [];
     const origin = cr.isChromeOS ? print_preview.DestinationOrigin.CROS :
                                    print_preview.DestinationOrigin.LOCAL;
     // Five destinations. FooDevice is the system default.