Google Chrome - hidden and invisible extensions by default

Chrome does hide some internal extensions , you can see them right here: chrome://system/

Could Google use them for tracking? How to delete them?

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List of extensions i see:

gfdkimpbcpahaombhbimeihdjnejgicl : Feedback : version 1_0

kmendfapggjehodndflmmgagdbamhnfd : CryptoTokenExtension : version 0_9_73

mfehgcgbbipciphmccgaenjidiccnmng : Cloud Print : version 0_1

mhjfbmdgcfjbbpaeojofohoefgiehjai : Chrome PDF Viewer : version 1

neajdppkdcdipfabeoofebfddakdcjhd : Google Network Speech : version 1_0

nkeimhogjdpnpccoofpliimaahmaaome : Google Hangouts : version 1_3_10

nmmhkkegccagdldgiimedpiccmgmieda : Chrome Web Store-Zahlungen : version 1_0_0_4

pkedcjkdefgpdelpbcmbmeomcjbeemfm : Chrome Media Router : version 7118_1015_0_0