New vpython to depot tools.

Changes in this release:
55ee5cd215996e99b807bd19060f8c6845423985 Switch to a buffered channel.
c18f898c8628f7063328a553de31b5a13ebbd47a Fix comment typos.
c55184b5835c789d073ce8ba10745cc7efedcd65 Fix typo
50e0d6a61bf2706e8096a4c3785331f2fa1f2bad Fix some warnings that are causing presubmit errors for the 2.7 fork.
39ca9cb80c0c7f5a18bcdcc6ce65bfdb1cc64879 Update vpython deployment doc
c93fd3c5ebdc3999eea86a7623dbd1ed4b40bc78 Roll chromiumos/config manually to fix the broken roller
149a1934123a29ca32c85f73597e7ffbfa7dbf4a Add initial PRESUBMIT support for linting python3

Change-Id: I1155342ace04e2944a9abe531e0f8b5d0206a0eb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3951269
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>
Auto-Submit: Brian Ryner <bryner@google.com>

cipd_manifest.txt

@@ -35,7 +35,7 @@ $VerifiedPlatform linux-386 linux-ppc64 linux-ppc64le linux-s390x
 $VerifiedPlatform linux-armv6l linux-mips64 linux-mips64le linux-mipsle
 
 # vpython.
-infra/tools/luci/vpython/${platform} git_revision:7979d954927af292bd5a57dd398a9791cc43099c
+infra/tools/luci/vpython/${platform} git_revision:788e09418ced22000a9774e4549b9ad42084b814
 
 # LUCI editor
 infra/tools/luci/led/${platform} git_revision:f09dbc988cae854052bc20d21a90089d9c188119

cipd_manifest.versions

@@ -354,56 +354,56 @@ infra/tools/luci/lucicfg/windows-amd64
 	CK-vX6Ylw1MJN71t_NcKFraKbFW9FEo4D4pQT9tE030C
 
 infra/tools/luci/vpython/linux-386
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	oWGrgk_ANcTVHjndYUOfroQ0Via73p9mRKjMJJwAgGUC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	-DqrW1YY1T_BnoblxXK5gsXsxLIlI3UiNijgKDCHVXIC
 
 infra/tools/luci/vpython/linux-amd64
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	XQxtJPiwHevSlqESfrtvcTcnyr5RFdhZ6SObC-qjr8AC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	Gz9krHL6kKjbvGdxI5atUyCuwSXBMIhmVrK6FblTzSIC
 
 infra/tools/luci/vpython/linux-arm64
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	t1sAGa8hCJOJcv6e44SeKgGHLcgRZeXel7mhFapILQgC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	j94ptZ4Jhqb7Kucuc5sUtMvNTihGNp07xqwmtYeyAKcC
 
 infra/tools/luci/vpython/linux-armv6l
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	FHXhLnb5LfKlHuSm7N7vzn178SUCnXAjlMc-gTnTNA4C
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	YHClLkt2SXTET3UPWDUEerzAbPL49QCzBzPmCXPrYFoC
 
 infra/tools/luci/vpython/linux-mips64
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	rtv3q-b6v3bGxSw_9fRAUCFgF2aQDMFmgo8zLdjZ1skC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	VOe-uQoFiAg-7ZZRFRXt4EKwTGiveObQ-LrO-iJiIr0C
 
 infra/tools/luci/vpython/linux-mips64le
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	0N8_eK_phLZKyffC_ru_fvGhlfNOImcx1hHansGygYMC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	9m723rVpHjKQFaFZoO07pdPS4ihDkFMMwJOmEmmBGWcC
 
 infra/tools/luci/vpython/linux-mipsle
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	b_DJybwJ7yVrBomaYzBQ0_P0uVJUe5VG4V10mRoCN7QC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	-64acFnU24T7vjNLAZhudYzf_S_8TTPZs5M4aOVrcW4C
 
 infra/tools/luci/vpython/linux-ppc64
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	UOn_WPwePhYfsNM5QU4gGVDRjfbtlz0BcB6NZu_Y2nwC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	exYhv24o623wpCvYMC712pZeIrLqGbbj7N2KnKh2mVsC
 
 infra/tools/luci/vpython/linux-ppc64le
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	MR6WkJx-4q79MT1zekQ14QdSxp8SUBSKwSA0y_KHWwAC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	yLpdb8_BtEP0ou_OILEQQFhCrsm3BCK_f29NwFBR5n0C
 
 infra/tools/luci/vpython/linux-s390x
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	ddiKQzp4n0mzM3OpFGCVoP644xDpMVyvyYWcBbmlFBYC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	Iy7mX6ddOS6xw7RJL_ZaC7wZW5PvJBamVVIelOeA5OcC
 
 infra/tools/luci/vpython/mac-amd64
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	sHTNOb-AAR9CPfuL5J314LNsJr0ZpCnQwwn1Cfxci_gC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	HNfbeV0kNVgfOttEgK-fq538CSP9Q5e0aXCoewaiw08C
 
 infra/tools/luci/vpython/mac-arm64
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	_j19AOaSSjnz6gnknkrkQNyUA8nWHNwFmV_4mJC5gkcC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	8g1b8S-MpuAv-K5pBtjvNCzaPZbH1KBeMIgJfYx-PjkC
 
 infra/tools/luci/vpython/windows-amd64
-	git_revision:7979d954927af292bd5a57dd398a9791cc43099c
-	yBWGUVYTDDCzwvrFWfB5W5GIRSKndvSK75M1m8l5qfUC
+	git_revision:788e09418ced22000a9774e4549b9ad42084b814
+	9xwbxh5Xhwkp_6m5F96fosvt7HuBtDp9oqHJU4urhxYC
 
 infra/tools/mac_toolchain/mac-amd64
 	git_revision:febf962fa9e6f5cc5c4ce86e8dab6ff6d91088dc