Waterfall is red. The revert [1] got a CR-1, so I'll try to fix forward.

Example failure:
[3024/18964] OBJCXX obj/ios/chrome/browser/ui/autofill/manual_fill/manual_fill_ui/manual_fill_cell_utils.o
FAILED: obj/ios/chrome/browser/ui/autofill/manual_fill/manual_fill_ui/manual_fill_cell_utils.o 
/b/s/w/ir/cache/goma/client/gomacc ../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF obj/ios/chrome/browser/ui/autofill/manual_fill/manual_fill_ui/manual_fill_cell_utils.o.d -DV8_DEPRECATION_WARNINGS -DNO_TCMALLOC -DCHROMIUM_BUILD -DFIELDTRIAL_TESTING_ENABLED -DCR_XCODE_VERSION=1010 -DCR_CLANG_REVISION=\"346388-1\" -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D_FORTIFY_SOURCE=2 -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DNS_BLOCK_ASSERTIONS=1 -DWEBP_EXTERN=extern -DEXPAT_RELATIVE_PATH -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DHAVE_PTHREAD -DSK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS -DSK_HAS_PNG_LIBRARY -DSK_HAS_WEBP_LIBRARY -DSK_SUPPORT_GPU=0 -DI18N_ADDRESS_VALIDATION_DATA_URL=\"https://chromium-i18n.appspot.com/ssl-aggregate-address/\" -DLEVELDB_PLATFORM_CHROMIUM=1 -DLEVELDB_PLATFORM_CHROMIUM=1 -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DUSE_CHROMIUM_ICU=1 -DU_STATIC_IMPLEMENTATION -DICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE -DUCHAR_TYPE=uint16_t -I../.. -Igen -I../../third_party/libwebp/src -I../../third_party/libyuv/include -I../../third_party/protobuf/src -Igen/protoc_out -I../../third_party/protobuf/src -I../../third_party/boringssl/src/include -I../../skia/config -I../../skia/ext -I../../third_party/skia/include/c -I../../third_party/skia/include/config -I../../third_party/skia/include/core -I../../third_party/skia/include/docs -I../../third_party/skia/include/effects -I../../third_party/skia/include/encode -I../../third_party/skia/include/gpu -I../../third_party/skia/include/pathops -I../../third_party/skia/include/ports -I../../third_party/skia/include/utils -I../../third_party/skia/modules/skottie/include -I../../third_party/libaddressinput/src/cpp/include -I../../third_party/leveldatabase -I../../third_party/leveldatabase/src -I../../third_party/leveldatabase/src/include -I../../third_party/icu/source/common -I../../third_party/icu/source/i18n -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -Wno-builtin-macro-redefined -D__DATE__= -D__TIME__= -D__TIMESTAMP__= -fcolor-diagnostics -fmerge-all-constants -Xclang -mllvm -Xclang -instcombine-lower-dbg-declare=0 -no-canonical-prefixes -arch armv7 -Wall -Werror -Wextra -Wimplicit-fallthrough -Wthread-safety -Wunguarded-availability -Wundeclared-selector -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-unneeded-internal-declaration -Wno-undefined-var-template -Wno-null-pointer-arithmetic -Wno-ignored-pragma-optimize -Wno-defaulted-function-deleted -Oz -fno-omit-frame-pointer -gdwarf-2 -isysroot /b/s/w/ir/cache/xcode_ios_10b61.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.1.sdk -stdlib=libc++ -miphoneos-version-min=10.0 -fvisibility=hidden -Xclang -load -Xclang ../../third_party/llvm-build/Release+Asserts/lib/libFindBadConstructs.dylib -Xclang -add-plugin -Xclang find-bad-constructs -Xclang -plugin-arg-find-bad-constructs -Xclang enforce-in-thirdparty-webkit -Xclang -plugin-arg-find-bad-constructs -Xclang check-enum-max-value -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -std=c++14 -fobjc-call-cxx-cdtors -fno-exceptions -fno-rtti -fvisibility-inlines-hidden -fobjc-arc -c ../../ios/chrome/browser/ui/autofill/manual_fill/manual_fill_cell_utils.mm -o obj/ios/chrome/browser/ui/autofill/manual_fill/manual_fill_ui/manual_fill_cell_utils.o
../../ios/chrome/browser/ui/autofill/manual_fill/manual_fill_cell_utils.mm:69:23: error: 'constraintEqualToSystemSpacingBelowAnchor:multiplier:' is only available on iOS 11.0 or newer [-Werror,-Wunguarded-availability-new]
                      constraintEqualToSystemSpacingBelowAnchor:previousAnchor
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/xcode_ios_10b61.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.1.sdk/System/Library/Frameworks/UIKit.framework/Headers/NSLayoutAnchor.h:79:1: note: 'constraintEqualToSystemSpacingBelowAnchor:multiplier:' has been explicitly marked partial here
- (NSLayoutConstraint *)constraintEqualToSystemSpacingBelowAnchor:(NSLayoutYAxisAnchor *)anchor multiplier:(CGFloat)multiplier API_AVAILABLE(ios(11.0),tvos(11.0));
^
../../ios/chrome/browser/ui/autofill/manual_fill/manual_fill_cell_utils.mm:69:23: note: enclose 'constraintEqualToSystemSpacingBelowAnchor:multiplier:' in an @available check to silence this warning
                      constraintEqualToSystemSpacingBelowAnchor:previousAnchor
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../ios/chrome/browser/ui/autofill/manual_fill/manual_fill_cell_utils.mm:77:21: error: 'constraintEqualToSystemSpacingBelowAnchor:multiplier:' is only available on iOS 11.0 or newer [-Werror,-Wunguarded-availability-new]
                    constraintEqualToSystemSpacingBelowAnchor:previousAnchor
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/b/s/w/ir/cache/xcode_ios_10b61.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS12.1.sdk/System/Library/Frameworks/UIKit.framework/Headers/NSLayoutAnchor.h:79:1: note: 'constraintEqualToSystemSpacingBelowAnchor:multiplier:' has been explicitly marked partial here
- (NSLayoutConstraint *)constraintEqualToSystemSpacingBelowAnchor:(NSLayoutYAxisAnchor *)anchor multiplier:(CGFloat)multiplier API_AVAILABLE(ios(11.0),tvos(11.0));
^
../../ios/chrome/browser/ui/autofill/manual_fill/manual_fill_cell_utils.mm:77:21: note: enclose 'constraintEqualToSystemSpacingBelowAnchor:multiplier:' in an @available check to silence this warning
                    constraintEqualToSystemSpacingBelowAnchor:previousAnchor
                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 errors generated.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/1329967