Add autorefresh_list experiment

This experiment/feature checks at regular intervals whether there are
updates to thread lists, and notifies the user via a snackbar when
an update exists.

Bug: #42
Change-Id: I98e4aa03a7080c6bff781ce7c850477433090957
diff --git a/src/injections/autorefresh_list.css b/src/injections/autorefresh_list.css
new file mode 100644
index 0000000..56d3fda
--- /dev/null
+++ b/src/injections/autorefresh_list.css
@@ -0,0 +1,79 @@
+.TWPT-pane-for-snackbar {
+  height: 48px;
+  position: fixed;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  z-index: 9999;
+  display: flex;
+  pointer-events: none;
+}
+
+.TWPT-snackbar {
+  display: flex;
+  align-self: flex-end;
+  justify-content: center;
+  flex: 1;
+  font-size: 15px;
+  font-weight: 400;
+  overflow: hidden;
+  pointer-events: none!important;
+}
+
+.TWPT-snackbar .TWPT-animation-container {
+  max-width: 616px;
+  min-width: 320px;
+  overflow: hidden;
+  pointer-events: auto;
+  transition: all 218ms cubic-bezier(.4, 0, 1, 1);
+}
+
+.TWPT-notification-bar {
+  background: #323232;
+  border-radius: 2px;
+  box-sizing: border-box;
+  color: #fff;
+  display: flex;
+  height: 48px;
+  padding: 6px 24px;
+}
+
+.TWPT-notification-bar focus-trap {
+  display: flex;
+  width: 100%;
+}
+
+.TWPT-notification-bar .TWPT-focus-content-wrapper {
+  display: flex;
+  height: 100%;
+  width: 100%;
+  max-height: inherit;
+  min-height: inherit;
+}
+
+.TWPT-notification-bar .TWPT-badge {
+  margin: auto 10px auto 0;
+}
+
+.TWPT-notification-bar .TWPT-message {
+  display: flex;
+  margin: auto;
+  flex: 1;
+  white-space: pre-line;
+}
+
+.TWPT-notification-bar .TWPT-action {
+  display: flex;
+  align-items: center;
+  color: #c6dafc;
+  cursor: pointer;
+  font-size: 14px;
+  font-weight: 700;
+  margin-left: 24px;
+  padding: 0;
+  text-transform: uppercase;
+}
+
+.TWPT-snackbar.TWPT-hidden {
+  display: none;
+}