sync: Additional cleanup of SyncOp #1605

Job	Run time
code-format	28s
check_vvl	1m 7s
chromium (target_os="linux" target_cpu="x64")	8m 18s
android (arm64-v8a, ON, c++_shared)	13m 32s
linux (address sanitizer, debug, robinhood ON )	35m 8s
chromium (target_os="android" target_cpu="arm64")	12m 50s
android (armeabi-v7a, OFF, c++_static)	9m 14s
androidOnLinux	19m 10s
linux (address sanitizer, release, robinhood ON )	44m 33s
linux (address sanitizer, release, robinhood OFF )	44m 20s
linux (thread sanitizer, release, robinhood ON )	22m 19s
mingw	17m 15s
windows (amd64)	15m 5s
windows (amd64_x86)	14m 33s
androidUpload	0s
windowsUpload	0s
iOS	6m 0s
linux Upload	0s
	4h 23m 52s

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