Print Preview Componentization: Put fit to page in correct tab order

Use tabindex=1 so it is focused before the scaling number input. When
the checkbox appears it is above the number input so should be focused
first.

Bug: 864452
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: I42d7841e89f9bd6098f9ff8a9ff4934270c391c9
Reviewed-on: https://chromium-review.googlesource.com/1140495
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575963}

chrome/browser/resources/print_preview/new/scaling_settings.html

@@ -10,7 +10,7 @@
   <template>
     <style include="print-preview-shared checkbox-radio">
     </style>
-    <print-preview-number-settings-section max-value=200 min-value=10
+    <print-preview-number-settings-section max-value="200" min-value="10"
         default-value="100" input-label="$i18n{scalingLabel}"
         disabled="[[disabled]]" current-value="{{currentValue_}}"
         input-valid="{{inputValid_}}" hint-message="$i18n{scalingInstruction}"
@@ -18,7 +18,7 @@
       <div slot="opt-outside-content" class="checkbox"
           hidden$="[[!settings.fitToPage.available]]">
         <label aria-live="polite">
-          <input type="checkbox" id="fit-to-page-checkbox"
+          <input type="checkbox" id="fit-to-page-checkbox" tabindex="1"
               disabled$="[[getDisabled_(disabled, inputValid_)]]"
               on-change="onFitToPageChange_">
           <span>$i18n{optionFitToPage}</span>