MD Settings: Restore focus after exiting various subpages.

chrome/browser/resources/settings/printing_page/printing_page.js

Index: chrome/browser/resources/settings/printing_page/printing_page.js
diff --git a/chrome/browser/resources/settings/printing_page/printing_page.js b/chrome/browser/resources/settings/printing_page/printing_page.js
index a58001fbe48169c3ecbfe61c6a7eef9ea6682204..762e8db9a852009a473483d8b7d209605040cb7c 100644
--- a/chrome/browser/resources/settings/printing_page/printing_page.js
+++ b/chrome/browser/resources/settings/printing_page/printing_page.js
@@ -34,12 +34,26 @@ Polymer({
     searchTerm: {
       type: String,
     },
+
+    /** @private {?Map<string, string>} */
+    focusConfig_: Object,
   },
 
   listeners: {
     'show-cups-printer-details': 'onShowCupsPrinterDetailsPage_',
   },
 
+  /** @override */
+  ready: function() {
+    this.focusConfig_ = new Map();
+    this.focusConfig_.set(
+        settings.Route.CLOUD_PRINTERS.path, '#cloudPrinters .subpage-arrow');
+// <if expr="chromeos">
+    this.focusConfig_.set(
+        settings.Route.CUPS_PRINTERS.path, '#cupsPrinters .subpage-arrow');
+// </if>
+  },
+
 // <if expr="chromeos">
   /** @private */
   onTapCupsPrinters_: function() {