I could not consistently repro this bug but feel it is important to report this bug. 

Device 1:
Mac laptop Chrome Version: (copy from chrome://version)
Google Chrome	66.0.3359.81 (Official Build) (64-bit)
Revision	fb2352fc7d3d530687ff90d6ccc195efd640c1a7-refs/branch-heads/3359@{#569}
OS	Mac OS X
JavaScript	V8 6.6.346.19
Flash	29.0.0.113 /Users/jiewu/Library/Application Support/Google/Chrome/PepperFlash/29.0.0.113/PepperFlashPlayer.plugin

Device 2:
iPad Chrome Version: 66.0.3359.82 (Chrome Beta) 

What steps will reproduce the problem?
(1) Sign in to Chrome on device 1 and device 2
(2) Add some bookmark folders in device 1
(3) Sync between device 1 and device 2
(4) Delete those folder created in step (2) and sync

What is the expected result?
Those bookmark folders are also deleted from device 2

What happens instead?
Those bookmark folders are not deleted from device 2

This is my first to take ownership to run testing. If there is anything I missed to cause this issue, please kindly let me know. Thanks.