History: Prevent search box from disappearing when search term is deleted.

Also removed unnecessary calls to updateNavBar_().

This fix is based on http://crrev.com/219018, which had to be reverted
because it introduced a regression.

BUG=263870
TEST=See repro steps in bug.
R=jhawkins@chromium.org

Review URL: https://codereview.chromium.org/23464026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@221512 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/history/history.js

@@ -938,6 +938,13 @@ HistoryView.prototype.onModelReady = function(doneLoading) {
     document.body.classList.remove('has-results');
 
   this.updateNavBar_();
+
+  if (isMobileVersion()) {
+    // Hide the search field if it is empty and there are no results.
+    var hasResults = this.model_.visits_.length > 0;
+    var isSearch = this.model_.getSearchText().length > 0;
+    $('search-field').hidden = !(hasResults || isSearch);
+  }
 };
 
 /**
@@ -1298,7 +1305,6 @@ HistoryView.prototype.displayResults_ = function(doneLoading) {
           createElementWithClassName('div', 'no-results-message'));
       noResults.textContent = loadTimeData.getString('noResults');
       this.resultDiv_.appendChild(resultsFragment);
-      this.updateNavBar_();
       return;
     }
 
@@ -1326,7 +1332,6 @@ HistoryView.prototype.displayResults_ = function(doneLoading) {
     // Add all the days and their visits to the page.
     this.resultDiv_.appendChild(resultsFragment);
   }
-  this.updateNavBar_();
 };
 
 /**
@@ -1335,9 +1340,10 @@ HistoryView.prototype.displayResults_ = function(doneLoading) {
  */
 HistoryView.prototype.updateNavBar_ = function() {
   this.updateRangeButtons_();
+
+  // Managed users have the control bar on top, don't show it on the bottom
+  // as well.
   if (!loadTimeData.getBoolean('isManagedProfile')) {
-    // Managed users have the control bar on top, don't show it on the bottom
-    // as well.
     $('newest-button').hidden = this.pageIndex_ == 0;
     $('newer-button').hidden = this.pageIndex_ == 0;
     $('older-button').hidden =

chrome/browser/resources/history/history_mobile.css

@@ -81,11 +81,6 @@ html[dir='rtl'] #search-field {
   background-position: right 16px center;
 }
 
-/* Hide the search field if it is empty (!valid) and there are no results. */
-body:not(.has-results) #search-field:not(:valid) {
-  display: none;
-}
-
 .no-results-message {
   margin-bottom: 1em;
   padding-left: 16px;