[MD History] Add keyboard navigation to the main history list.

chrome/browser/resources/md_history/history_list.html

Index: chrome/browser/resources/md_history/history_list.html
diff --git a/chrome/browser/resources/md_history/history_list.html b/chrome/browser/resources/md_history/history_list.html
index 7947550fea4048de72e4a4c578b8226af132251b..e2a1906e6208f4c355fd91374ef5a3498ea48b18 100644
--- a/chrome/browser/resources/md_history/history_list.html
+++ b/chrome/browser/resources/md_history/history_list.html
@@ -27,7 +27,8 @@
     <iron-list items="{{historyData_}}" as="item" id="infinite-list"
         hidden$="[[!hasResults(historyData_.length)]]">
       <template>
-        <history-item item="[[item]]"
+        <history-item tabindex$="[[tabIndex]]"
+            item="[[item]]"
             selected="{{item.selected}}"
             is-card-start="[[isCardStart_(item, index, historyData_.length)]]"
             is-card-end="[[isCardEnd_(item, index, historyData_.length)]]"
@@ -35,7 +36,9 @@
             search-term="[[searchedTerm]]"
             number-of-items="[[historyData_.length]]"
             path="[[pathForItem_(index)]]"
-            index="[[index]]">
+            index="[[index]]"
+            iron-list-tab-index="[[tabIndex]]"
+            last-focused="{{lastFocused_}}">
         </history-item>
       </template>
     </iron-list>