[ChromeOS] Reland - Make WebUI login use only needed resources.

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

Index: chrome/browser/resources/chromeos/login/screen_gaia_signin.css
diff --git a/chrome/browser/resources/chromeos/login/screen_signin.css b/chrome/browser/resources/chromeos/login/screen_gaia_signin.css
similarity index 85%
rename from chrome/browser/resources/chromeos/login/screen_signin.css
rename to chrome/browser/resources/chromeos/login/screen_gaia_signin.css
index f28ccd4a1fb6af9005142ea71e145080bc306ab5..9d4a8f3a8d096378875fe6d24b549d964bd828b4 100644
--- a/chrome/browser/resources/chromeos/login/screen_signin.css
+++ b/chrome/browser/resources/chromeos/login/screen_gaia_signin.css
@@ -3,13 +3,6 @@
  * found in the LICENSE file.
  */
 
-#signin {
-  -webkit-box-align: center;
-  -webkit-box-pack: center;
-  display: -webkit-box;
-  overflow: hidden;
-}
-
 #gaia-signin {
   -webkit-box-align: center;
   -webkit-box-pack: center;
@@ -61,9 +54,3 @@ html[dir=rtl] #signin-right {
   right: 0;
   top: 0;
 }
-
-#email,
-#password {
-  display: block;
-  margin-bottom: 20px;
-}