In order to make sure it's a
tab, you can click the «show / hide» button, that looks like a backwards «P» with a double
vertical bar (it's a paragraph mark), and
tabs will show up as an arrow pointing to the right.
To switch back to the old way of doing things and display open
tabs within Chrome, open up the Chrome app and tap the three
vertical dots on the right - hand side of the address
bar.