Settings: Implement sub-subpages, and clean up some animations.

chrome/browser/resources/settings/search_page/search_page.js

Index: chrome/browser/resources/settings/search_page/search_page.js
diff --git a/chrome/browser/resources/settings/search_page/search_page.js b/chrome/browser/resources/settings/search_page/search_page.js
index f0b9fc4bde1f9a8f0f1f869f176f0ba37b3da1d6..fc03c5810d4bb7c3dd1dd4c30823324621a728a2 100644
--- a/chrome/browser/resources/settings/search_page/search_page.js
+++ b/chrome/browser/resources/settings/search_page/search_page.js
@@ -118,6 +118,11 @@ Polymer({
   },
 
   /** @private */
+  searchEnginesSubpage_: function() {
+    this.$.pages.navigateTo('search-engines-subpage');
+  },
+
+  /** @private */
   handleBack_: function() {
     this.$.pages.back();
   },