ChromeOS OOBE: display icons specific to screen DPI.

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

Index: chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css
diff --git a/chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css b/chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css
index d825a6176ab1a18c300ca0573be23ed692b19e77..61e82d5a071328ccdaa9a7cbb7323e7830d6e806 100644
--- a/chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css
+++ b/chrome/browser/resources/chromeos/login/oobe_welcome_secondary_button.css
@@ -51,3 +51,15 @@ iron-icon {
   color: #5a5a5a;
   margin: 0 8px 0 0;
 }
+
+@media all and (-webkit-max-device-pixel-ratio: 1.5) {
+  #icon2x {
+    display: none;
+  }
+}
+
+@media all and (-webkit-min-device-pixel-ratio: 1.5) {
+  #icon1x {
+    display: none;
+  }
+}