Fix MD display settings when the display supports a single resolution

chrome/browser/resources/settings/controls/settings_slider.js

Index: chrome/browser/resources/settings/controls/settings_slider.js
diff --git a/chrome/browser/resources/settings/controls/settings_slider.js b/chrome/browser/resources/settings/controls/settings_slider.js
index c6b9b59e007198601fa4935a3b07ec8cdf929234..1d7e2a94372ca4f788a7972bb1dc37e8c08cf372 100644
--- a/chrome/browser/resources/settings/controls/settings_slider.js
+++ b/chrome/browser/resources/settings/controls/settings_slider.js
@@ -50,11 +50,15 @@ Polymer({
    * @private
    */
   onSliderChanged_: function() {
+    var sliderValue = isNaN(this.$.slider.immediateValue)
+                         ? this.$.slider.value
+                         : this.$.slider.immediateValue;
+
     var newValue;
     if (this.tickValues && this.tickValues.length > 0)
-      newValue = this.tickValues[this.$.slider.immediateValue];
+      newValue = this.tickValues[sliderValue];
     else
-      newValue = this.$.slider.immediateValue;
+      newValue = sliderValue;
 
     this.set('pref.value', newValue);
   },