Unified icon-buttons used in the new GAIA flow.

chrome/browser/resources/chromeos/login/gaia_icon_button.css

Index: chrome/browser/resources/chromeos/login/gaia_icon_button.css
diff --git a/chrome/browser/resources/chromeos/login/gaia_icon_button.css b/chrome/browser/resources/chromeos/login/gaia_icon_button.css
new file mode 100644
index 0000000000000000000000000000000000000000..dc61a0a88c3aaf5c090a6904b76ccee94efcb34b
--- /dev/null
+++ b/chrome/browser/resources/chromeos/login/gaia_icon_button.css
@@ -0,0 +1,31 @@
+/* Copyright 2015 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+:host {
+  background: transparent;
+  border: none;
+  border-radius: 50%;
+  height: 24px;
+  margin: 0;
+  outline: none;
+  padding: 0;
+  width: 24px;
+}
+
+:host(:hover) {
+  cursor: pointer;
+}
+
+:host(:focus) {
+  background: rgba(0, 0, 0, .16);
+  border-color: transparent;
+  opacity: 0.75;
+}
+
+:host(:active) {
+  background: rgba(0, 0, 0, .12);
+  opacity: 1.0;
+}
+