Revert "Merge pull request #4316 from guardian/polyfill"

Seems like my polyfill implementation broke the Omniture confidence again... :frowning: 

This reverts commit d2f1ecf13193ee45b5b1aeb74b692b0b27c99c32, reversing
changes made to 52112d2a16ddd6bea14c96948507e83a03e64fb4.