Fix -Wswitch warning in Mouse #11

Job	Run time
build (x64-Debug-UWP, amd64)	1m 59s
build (x64-Release-UWP, amd64)	1m 56s
build (x64-Debug-UWP-Clang, amd64)	2m 50s
build (x64-Release-UWP-Clang, amd64)	2m 21s
build (x86-Debug-UWP, amd64_x86)	1m 56s
build (x86-Release-UWP, amd64_x86)	1m 52s
build (x86-Debug-UWP-Clang, amd64_x86)	2m 19s
build (x86-Release-UWP-Clang, amd64_x86)	2m 37s
build (arm64-Debug-UWP, amd64_arm64)	1m 57s
build (arm64-Release-UWP, amd64_arm64)	1m 39s
build (arm64-Debug-UWP-Clang, amd64_arm64)	1m 59s
build (arm64-Release-UWP-Clang, amd64_arm64)	2m 6s
	25m 31s

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