Print Preview: Polymer 3 cleanups

- Use Polymer 3 syntax for custom elements created/defined in tests.
- Remove assetpath="chrome://resources/", which is automatically
added by the autogeneration code for style modules, but does not
make sense for modules inside of Print Preview.
- Remove unused generated_path variable
- Rename bundled Print Preview JS resource as PRINT_PREVIEW_ROLLUP_JS
to indicate that this file was generated by rollup.

Bug: 1012574
Change-Id: I37fe3228b1e6b1811b8bfed6abf4f4784d5e7587
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1919908Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#716470}

chrome/browser/resources/print_preview/print_preview_resources_vulcanized.grd

@@ -13,7 +13,7 @@
   <release seq="1">
     <includes>
       <include name="IDR_PRINT_PREVIEW_VULCANIZED_HTML" file="${root_gen_dir}\chrome\browser\resources\print_preview\vulcanized.html" use_base_dir="false" preprocess="true" compress="gzip" type="BINDATA" />
-      <include name="IDR_PRINT_PREVIEW_PRINT_PREVIEW_JS" file="${root_gen_dir}\chrome\browser\resources\print_preview\print_preview.js" use_base_dir="false" preprocess="true" compress="gzip" type="BINDATA" />
+      <include name="IDR_PRINT_PREVIEW_PRINT_PREVIEW_ROLLUP_JS" file="${root_gen_dir}\chrome\browser\resources\print_preview\print_preview.js" use_base_dir="false" preprocess="true" compress="gzip" type="BINDATA" />
     </includes>
   </release>
 </grit>

chrome/browser/resources/print_preview/ui/print_preview_shared_css.js

@@ -10,6 +10,6 @@ import {html, Polymer} from 'chrome://resources/polymer/v3_0/polymer/polymer_bun
 
 const template = document.createElement('template');
 template.innerHTML = `
-<dom-module id="print-preview-shared" assetpath="chrome://resources/">{__html_template__}</dom-module>
+<dom-module id="print-preview-shared">{__html_template__}</dom-module>
 `;
 document.body.appendChild(template.content.cloneNode(true));

chrome/browser/resources/print_preview/ui/throbber_css.js

@@ -6,6 +6,6 @@ import {html, Polymer} from 'chrome://resources/polymer/v3_0/polymer/polymer_bun
 
 const template = document.createElement('template');
 template.innerHTML = `
-<dom-module id="throbber" assetpath="chrome://resources/">{__html_template__}</dom-module>
+<dom-module id="throbber">{__html_template__}</dom-module>
 `;
 document.body.appendChild(template.content.cloneNode(true));

chrome/browser/ui/webui/print_preview/print_preview_ui.cc

@@ -403,13 +403,10 @@ content::WebUIDataSource* CreatePrintPreviewUISource(Profile* profile) {
   source->EnableReplaceI18nInJS();
 #if BUILDFLAG(OPTIMIZE_WEBUI)
   source->AddResourcePath("print_preview.js",
-                          IDR_PRINT_PREVIEW_PRINT_PREVIEW_JS);
+                          IDR_PRINT_PREVIEW_PRINT_PREVIEW_ROLLUP_JS);
   source->SetDefaultResource(IDR_PRINT_PREVIEW_VULCANIZED_HTML);
 #else
   // Add all Print Preview resources.
-  std::string generated_path =
-      "@out_folder@/gen/chrome/browser/resources/print_preview/";
-
   for (size_t i = 0; i < kPrintPreviewResourcesSize; ++i) {
     std::string path = kPrintPreviewResources[i].name;
     if (path.rfind(kGeneratedPath, 0) == 0) {

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

@@ -330,14 +330,12 @@ export function triggerInputEvent(inputElement, input, parentElement) {
 }
 
 export function setupTestListenerElement() {
-  const domModule = document.createElement('dom-module');
-  domModule.setAttribute('id', 'test-listener-element');
-  domModule.appendChild(document.createElement('template'));
-  document.body.appendChild(domModule);
   Polymer({
     is: 'test-listener-element',
     behaviors: [WebUIListenerBehavior],
   });
+  const testElement = document.createElement('test-listener-element');
+  document.body.appendChild(testElement);
 }
 
 /** @return {!DestinationStore} */

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

@@ -4,7 +4,7 @@
 
 import {SelectBehavior} from 'chrome://print/print_preview.js';
 import {assert} from 'chrome://resources/js/assert.m.js';
-import {Polymer} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';
+import {html, Polymer} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';
 import {eventToPromise} from 'chrome://test/test_util.m.js';
 
 window.select_behavior_test = {};
@@ -23,20 +23,17 @@ suite(select_behavior_test.suiteName, function() {
 
   /** @override */
   setup(function() {
-    document.body.innerHTML = `
-            <dom-module id="test-select">
-              <template>
+    Polymer({
+      is: 'test-select',
+
+      _template: html`
         <select value="{{selectedValue::change}}">
           <option value="0" selected>0</option>
           <option value="1">1</option>
           <option value="2">2</option>
         </select>
-              </template>
-            </dom-module>
-          `;
+      `,
 
-    Polymer({
-      is: 'test-select',
       behaviors: [SelectBehavior],
 
       onProcessSelectChange: function(value) {