Developer Hamza Sood assisted 9to5Mac in locating a resource file which suggests the iPad mini will get support for the feature.
The resource file shown above from the upcoming OS X El Capitan’s Safari 9 browser shows support for a split-screen view of Safari on the iPad mini. Additionally, a developer tool in El Capitan for testing the responsiveness of website designs allows developers to simulate an iPad mini 3 (which does not support split-view) running Safari in a split-view mode. With both the testing capabilities and settings image present in the upcoming version of Safari, we believe that the functionality is coming in a future iPad mini update.
It's possible that Apple could debut a new iPad mini on September 9th alongside new iPhones and a new Apple TV. It would likely feature a faster processor and a design similar to the iPad Air 2.
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