Add back button to chrome://devices

chrome/browser/resources/local_discovery/local_discovery.css

Index: chrome/browser/resources/local_discovery/local_discovery.css
diff --git a/chrome/browser/resources/local_discovery/local_discovery.css b/chrome/browser/resources/local_discovery/local_discovery.css
index 08b38439a39c97f71bcc2c75c751281c7b7e0b4e..2ebcef985726ae4416bffb9af1d0956440db91c6 100644
--- a/chrome/browser/resources/local_discovery/local_discovery.css
+++ b/chrome/browser/resources/local_discovery/local_discovery.css
@@ -108,4 +108,20 @@ section {
 
 .dialog-contents {
     padding-left: 17px;
-}
+}
+
+#back-button {
+  background: url('chrome://theme/IDR_CHEVRON_LEFT') left no-repeat;
+  margin-bottom: 25px;
+  margin-top: 6px;
+  padding-left: 23px;
+}
+
+html[dir='rtl'] #back-button {
+  transform: scaleX(-1);
+}
+
+html[dir='rtl'] #back-button span {
+  display: inline-block;
+  transform: scaleX(-1);
+}