[MD settings] using h2 for sub-headers consistently.

chrome/browser/resources/settings/passwords_and_forms_page/autofill_section.html

Index: chrome/browser/resources/settings/passwords_and_forms_page/autofill_section.html
diff --git a/chrome/browser/resources/settings/passwords_and_forms_page/autofill_section.html b/chrome/browser/resources/settings/passwords_and_forms_page/autofill_section.html
index 2892c53b0187f66fc4232365eac454cb16fa2ece..f21df6173da9d17987fbecae94a1a655cd514a05 100644
--- a/chrome/browser/resources/settings/passwords_and_forms_page/autofill_section.html
+++ b/chrome/browser/resources/settings/passwords_and_forms_page/autofill_section.html
@@ -39,7 +39,7 @@
         color: var(--paper-grey-600);
       }
     </style>
-    <div class="heading">$i18n{addresses}</div>
+    <h2>$i18n{addresses}</h2>
     <div class="item-list">
       <div id="addressList" class="vertical-list list-section">
         <template is="dom-repeat" items="[[addresses]]">
@@ -72,7 +72,7 @@
           on-close="unstampAddressEditDialog_">
       </settings-address-edit-dialog>
     </template>
-    <div class="heading">$i18n{creditCards}</div>
+    <h2>$i18n{creditCards}</h2>

[hcarmona, 2016/08/24 23:41:21]

Looks like this add some extra space between the lists.

[dschuyler, 2016/08/25 02:00:53]

I was separating the CLs. I have more changes to go after this.

     <div class="item-list">
       <div class="list-item column-header">
         <div class="type-column">$i18n{creditCardType}</div>