iOS 8 and Yosemite Finally Allow to Close Tabs on Other Devices
Heureka! I never thought the day would come, but apparently we can now close other devices’ tabs from one device.
On iOS bring up the tab list and scroll to the bottom. It will list your iCloud Tabs on the bottom. Simply swipe to delete. A few moments later the tab will automatically close on the other device.
On OS X bring up iCloud Tabs and click the small X. A few moments later the tab will automatically close on the other device.