The only thing similar I can find is at about 1:22:00 in the keynote here https://youtu.be/Y2VF8tmLFHw but all he actually says is "silicon specific accelerators".
So honestly at this point it could mean anything.
"Google has clearly committed to this vision of AI on the phone. At I/O, the company also unveiled a custom-built chip for both training and running neural networks in its data centers. I asked Google CEO Sundar Pichai if the company might build its own mobile chip along the same lines. He said the company had no plans to do so, but he didn’t rule it out either. “If we don’t find the state-of-the-art available on the outside,” he said, “we try to push it there.”"
"Companies such as Intel are already working on this kind of mobile AI processor."
https://www.wired.com/2017/05/google-really-wants-put-ai-poc...
Edit - also:
"There’s already one mobile processor with a machine learning-specific DSP on the market today. The Qualcomm Snapdragon 835 system-on-a-chip sports the Hexagon DSP that supports TensorFlow. DSPs are also used for providing functionality like recognizing the “OK, Google” wake phrase for the Google Assistant, according to Moorhead."
http://www.pcworld.com/article/3197412/mobile/heres-how-goog...