diff -u b/core/tests/Drupal/Tests/Core/Extension/ThemeHandlerTest.php b/core/tests/Drupal/Tests/Core/Extension/ThemeHandlerTest.php
--- b/core/tests/Drupal/Tests/Core/Extension/ThemeHandlerTest.php
+++ b/core/tests/Drupal/Tests/Core/Extension/ThemeHandlerTest.php
@@ -156,8 +156,8 @@
     // Ensure that the css paths are set with the proper prefix.
     $this->assertEquals(array(
       'screen' => array(
-        'seven.base.css' => DRUPAL_ROOT . '/core/themes/seven/seven.base.css',
-        'style.css' => DRUPAL_ROOT . '/core/themes/seven/style.css',
+        'css/seven.base.css' => DRUPAL_ROOT . '/core/themes/seven/css/seven.base.css',
+        'css/style.css' => DRUPAL_ROOT . '/core/themes/seven/css/style.css',
         'css/layout.css' => DRUPAL_ROOT . '/core/themes/seven/css/layout.css',
         'css/components/buttons.css' => DRUPAL_ROOT . '/core/themes/seven/css/components/buttons.css',
         'css/components/buttons.theme.css' => DRUPAL_ROOT . '/core/themes/seven/css/components/buttons.theme.css',
@@ -171,8 +171,8 @@
     // Ensure that the css paths are set with the proper prefix.
     $this->assertEquals(array(
       'screen' => array(
-        'css/seven.base.css' => DRUPAL_ROOT . '/core/themes/seven/css/seven.base.css',
-        'css/style.css' => DRUPAL_ROOT . '/core/themes/seven/css/style.css',
+        'seven.base.css' => DRUPAL_ROOT . '/core/themes/seven/seven.base.css',
+        'style.css' => DRUPAL_ROOT . '/core/themes/seven/style.css',
         'css/layout.css' => DRUPAL_ROOT . '/core/themes/seven/css/layout.css',
         'css/components/buttons.css' => DRUPAL_ROOT . '/core/themes/seven/css/components/buttons.css',
         'css/components/buttons.theme.css' => DRUPAL_ROOT . '/core/themes/seven/css/components/buttons.theme.css',
only in patch2:
unchanged:
--- a/core/themes/seven/jquery.ui.theme.css
+++ b/core/themes/seven/css/jquery.ui.theme.css
@@ -64,26 +64,26 @@
   height: 16px;
   overflow: hidden;
   background-repeat: no-repeat;
-  background-image: url(images/ui-icons-222222-256x240.png);
+  background-image: url("../images/ui-icons-222222-256x240.png");
 }
 .ui-widget-content .ui-icon,
 .ui-widget-header .ui-icon {
-  background-image: url(images/ui-icons-222222-256x240.png);
+  background-image: url("../images/ui-icons-222222-256x240.png");
 }
 .ui-state-default .ui-icon {
-  background-image: url(images/ui-icons-888888-256x240.png);
+  background-image: url("../images/ui-icons-888888-256x240.png");
 }
 .ui-state-hover .ui-icon,
 .ui-state-focus .ui-icon,
 .ui-state-active .ui-icon {
-  background-image: url(images/ui-icons-454545-256x240.png);
+  background-image: url("../images/ui-icons-454545-256x240.png");
 }
 .ui-state-highlight .ui-icon {
-  background-image: url(images/ui-icons-800000-256x240.png);
+  background-image: url("../images/ui-icons-800000-256x240.png");
 }
 .ui-state-error .ui-icon,
 .ui-state-error-text .ui-icon {
-  background-image: url(images/ui-icons-ffffff-256x240.png);
+  background-image: url("../images/ui-icons-ffffff-256x240.png");
 }
 .ui-widget p .ui-icon {
   margin: 2px 3px 0 0;