Edit Mode Reduced significantly with TB Enabled

Description

With TB enabled on a space the edit mode is reduced significantly, resulting in it being impossible to edit a page. 

Steps to Reproduce

• Add a new skin, which will be the child of the root skin
• Select global skin which will be the skin you have just created. 
• Navigate to an existing page/space
• Edit the page.
• Notice the edit mode screen has shrunk considerably. 

Acceptance Criteria: 

• Ensure that the sizing of the edit mode screen returns to default 
• Ensure that all current supported versions are performing as expected. 
• Test the fix against the latest versions of Chrome, Firefox and IE.

Confluence Version Affected

• 6.15.2

Browser

• Chrome