Added functionality to bypass alerts

This is done with the following steps:
'I confirm all alerts' means that all alert and confirm windows are returned and returned true respectively
'I dismiss all alerts' means that all confirm windows are returned false
'I answer all prompts with "([^"]*)"' means that all prompts are returned with the given string

Please note that these settings are on a PER PAGE basis.  This means that for best results, the step must be given right before the alert is generated.

cms/djangoapps/contentstore/features/studio-overview-togglesection.feature

@@ -5,29 +5,27 @@ Feature: Overview Toggle Section
 
 	Scenario: The default layout for the overview page is to show sections in expanded view
 		Given I have a course with multiple sections
-    When I navigate to the course overview page
-    Then I see the "Collapse All Sections" link
-    And all sections are expanded
+        When I navigate to the course overview page
+        Then I see the "Collapse All Sections" link
+        And all sections are expanded
 
 	Scenario: Expand /collapse for a course with no sections
 		Given I have a course with no sections
-    When I navigate to the course overview page
-    Then I do not see the "Collapse All Sections" link
+        When I navigate to the course overview page
+        Then I do not see the "Collapse All Sections" link
 
 	Scenario: Collapse link appears after creating first section of a course
 		Given I have a course with no sections
-    When I navigate to the course overview page
-    And I add a section
-    Then I see the "Collapse All Sections" link
-    And all sections are expanded
+        When I navigate to the course overview page
+        And I add a section
+        Then I see the "Collapse All Sections" link
+        And all sections are expanded
 
-    # Skipped because Ubuntu ChromeDriver hangs on alert
-    @skip
 	Scenario: Collapse link is not removed after last section of a course is deleted
 		Given I have a course with 1 section
-    And I navigate to the course overview page
-    When I press the "section" delete icon
-    And I confirm the alert
+        And I navigate to the course overview page
+        When I confirm all alerts
+        And I press the "section" delete icon
 		Then I see the "Collapse All Sections" link
 
 	Scenario: Collapsing all sections when all sections are expanded

common/djangoapps/terrain/steps.py

@@ -159,3 +159,18 @@ def registered_edx_user(step, uname):
 @step(u'All dialogs should be closed$')
 def dialogs_are_closed(step):
     assert world.dialogs_closed()
+
+
+@step('I confirm all alerts')
+def i_confirm_with_ok(step):
+    world.browser.execute_script('window.confirm = function(){return true;} ; window.alert = function(){return;}')
+
+
+@step('I dismiss all alerts')
+def i_dismiss_with_ok(step):
+    world.browser.execute_script('window.confirm = function(){return false;}')
+
+
+@step('I answer all prompts with "([^"]*)"')
+def i_answer_prompts_with(step, prompt):
+    world.browser.execute_script('window.prompt = function(){return %s;}') % prompt