Polymer modulizer: Support ignore annotations

Support /* ignore */ annotations in Polymer modulizer, following the
same approach as the JS modulizer. This will be used to temporarily
migrate settings_idle_load and settings pages that depend on it, before
adding lazy loading to the Polymer 3 page.

Bug: 1026426
Change-Id: Iaf2b3d1e3ba69f97946039522d86ecf2739370cc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2092183Reviewed-by: dpapad <dpapad@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747951}

tools/polymer/polymer.py

@@ -351,6 +351,9 @@ def _process_dom_module(js_file, html_file):
   # Replace export annotations with 'export'.
   EXPORT_LINE_REGEX = '/* #export */'
 
+  # Ignore lines with an ignore annotation.
+  IGNORE_LINE_REGEX = '\s*/\* #ignore \*/(\S|\s)*'
+
   with io.open(js_file, encoding='utf-8') as f:
     lines = f.readlines()
 
@@ -393,6 +396,9 @@ def _process_dom_module(js_file, html_file):
       cr_define_end_line = i
       break
 
+    if re.match(IGNORE_LINE_REGEX, line):
+      line = ''
+
     line = _rewrite_namespaces(line)
     lines[i] = line
 

tools/polymer/polymer_test.py

@@ -76,6 +76,13 @@ class PolymerModulizerTest(unittest.TestCase):
         'dom-module', 'dom_module.html', 'dom_module_with_define.js',
         'dom_module_with_define.m.js', 'dom_module_with_define_expected.js')
 
+  # Test case where HTML is extracted from a Polymer2 <dom-module> that has
+  # ignore annotations.
+  def testDomModuleWithIgnore(self):
+    self._run_test('dom-module', 'dom_module.html', 'dom_module_with_ignore.js',
+                   'dom_module_with_ignore.m.js',
+                   'dom_module_with_ignore_expected.js')
+
   # Test case where HTML is extracted from a Polymer2 <dom-module> that also
   # uses <if expr> for imports.
   def testDomModuleWithConditionalImport(self):

tools/polymer/tests/dom_module_with_ignore.js

+Polymer({
+  is: 'cr-test-foo',
+  behaviors: [Polymer.PaperRippleBehavior],
+  /** @override */
+  ready() {
+    /* #ignore */ this.importHref('./foo.html');
+  },
+});

tools/polymer/tests/dom_module_with_ignore_expected.js

+import {Polymer, html} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';
+
+import {PaperRippleBehavior} from 'chrome://resources/polymer/v3_0/paper-behaviors/paper-ripple-behavior.js';
+// import 'chrome://resources/js/ignore_me.m.js';
+import '../shared_vars_css.m.js';
+import './foo.m.js';
+
+Polymer({
+  _template: html`<!--_html_template_start_-->
+    <style>
+      div {
+        font-size: 2rem;
+      }
+    </style>
+    <div>Hello world</div>
+<!--_html_template_end_-->`,
+  is: 'cr-test-foo',
+  behaviors: [PaperRippleBehavior],
+  /** @override */
+  ready() {
+  },
+});