Print Preview: Fix scrollbar page number ordering.

The displayed current page number in the PDF viewer's page indicator is
incorrect when the custom pages setting input is out of order. Sort
the pages before storing them in the settings so the page numbers are
displayed in the correct order.

Bug: 1015145
Change-Id: I56c0108bf2ae8c6dba9d44d5c0d0046a8b7b6b9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1867378
Commit-Queue: Daniel Hosseinian <dhoss@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707514}

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

@@ -247,6 +247,11 @@ Polymer({
         }
       }
     }
+
+    // Page numbers should be sorted to match the order of the pages in the
+    // rendered PDF.
+    pages.sort((left, right) => left - right);
+
     this.errorState_ = PagesInputErrorState.NO_ERROR;
     this.pagesToPrint_ = pages;
   },

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

@@ -150,6 +150,17 @@ cr.define('pages_settings_test', function() {
       await setCustomInput('1,2,3\u30011\u300156');
       validateState(
           [1, 2, 3, 56], [{from: 1, to: 3}, {from: 56, to: 56}], '', false);
+
+      // https://crbug.com/1015145
+      // Tests that the pages gets sorted for an unsorted input.
+      await setCustomInput('89-91, 3, 6, 46, 1, 4, 2-3');
+      validateState(
+          [1, 2, 3, 4, 6, 46, 89, 90, 91],
+          [
+            {from: 1, to: 4}, {from: 6, to: 6}, {from: 46, to: 46},
+            {from: 89, to: 91}
+          ],
+          '', false);
     });
 
     // Tests that the correct error messages are shown for different user