Chrome Version: 53.0.2785.144 (Official Build) (64-bit)
Chrome OS Version: 8530.93.0 (Official Build) stable-channel samus
Chrome OS Platform: Chromebook Pixel 2
Network info: N/A

Please specify Cr-* of the system to which this bug/feature applies (add
the label below).

Steps To Reproduce:
(1) Pinch to zoom on any Chrome page using track pad.  

Expected Result:
Chrome should zoom in or out.  This works using built in touch screen but not track pad.  This works on Mac and should be expected to work on any high quality large multi-touch track pad.  

Actual Result:
Nothing happens.

How frequently does this problem reproduce? (Always, sometimes, hard to
reproduce?)
Always 

What is the impact to the user, and is there a workaround? If so, what is
it?
Poor, frustrating user experience, particularly for uses coming from Mac to Chrome.

Please provide any additional information below. Attach a screen shot or
log if possible.