Improved sidebar tab switching performance.

Pretty much no lag now. Fixes #365.

resources/report/css/overrides.css

@@ -25,9 +25,11 @@ paper-icon-button[disabled] {
     bottom: 0;
     right: 0;
 }
-/* This stops transitions from overflowing onto other elements. */
-html /deep/ core-animated-pages {
-    overflow: hidden;
+/* This speeds up tab switching. The 1px height is so that core-list children
+   don't complain about not having a height set. */
+core-animated-pages::shadow ::content > *:not(.core-selected):not([animate]) {
+    display: block !important;
+    height: 1px;
 }
 /* This makes checkboxes have the same padding as icons in lists. */
 html /deep/ core-menu paper-checkbox::shadow #checkboxLabel {

resources/report/css/style.css

@@ -225,6 +225,7 @@ paper-item > a:hover {
 }
 #filters {
     padding: 8px 0;
+    overflow: hidden;
 }
 #filters > * {
     padding: 0 16px;