Improve user feedback on the Profile > Design page

- Header changes immediately without a page reload
- Lets the user know that we actually saved their setting when changed

features/profile/profile.feature

@@ -30,3 +30,16 @@ Feature: Profile
     Given I have activity
     When I visit profile history page
     Then I should see my activity
+
+  @javascript
+  Scenario: I change my application theme
+    Given I visit profile design page
+    When I change my application theme
+    Then I should see the theme change immediately
+    And I should receive feedback that the changes were saved
+
+  @javascript
+  Scenario: I change my code preview theme
+    Given I visit profile design page
+    When I change my code preview theme
+    Then I should receive feedback that the changes were saved

features/steps/profile/profile.rb

@@ -59,4 +59,21 @@ class Profile < Spinach::FeatureSteps
   Then 'I should see my activity' do
     page.should have_content "#{current_user.name} closed issue"
   end
+
+  When "I change my application theme" do
+    choose "Violet"
+  end
+
+  When "I change my code preview theme" do
+    choose "Dark code preview"
+  end
+
+  Then "I should see the theme change immediately" do
+    page.should have_selector('body.ui_color')
+    page.should_not have_selector('body.ui_basic')
+  end
+
+  Then "I should receive feedback that the changes were saved" do
+    page.should have_content("Saved")
+  end
 end