Update missing dependency

Author: alanrodas

app/elements/elements.html

@@ -39,7 +39,6 @@
 <link rel="import" href="../bower_components/paper-fab/paper-fab.html">
 <link rel="import" href="../bower_components/paper-dialog/paper-dialog.html">
 <link rel="import" href="../bower_components/paper-dialog-scrollable/paper-dialog-scrollable.html">
-<link rel="import" href="../bower_components/paper-tristate-checkbox/paper-tristate-checkbox.html">
 
 <!-- Localization -->
 <link rel="import" href="../bower_components/app-localize-behavior/app-localize-behavior.html">
@@ -90,3 +89,4 @@
 <link rel="import" href="../elements/results-inspector/results-inspector.html">
 <link rel="import" href="../elements/blocks-toolbox-selector/blocks-toolbox-selector.html">
 <link rel="import" href="../elements/report-issue/report-issue.html">
+<link rel="import" href="../elements/paper-tristate-checkbox/paper-tristate-checkbox.html">