chromium 66 FTBFS on armhf

FAILED: ../../../../../usr/bin/clang++-4.0 -MMD -MF obj/buildtools/third_party/libc++abi/libc++abi/cxa_exception.o.d -DLIBCXXABI_SILENT_TERMINATE -DV8_DEPRECATION_WARNINGS -DUSE_UDEV -DUSE_AURA=1 -DUSE_GLIB=1 -DUSE_NSS_CERTS=1 -DUSE_X11=1 -DNO_TCMALLOC -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DOFFICIAL_BUILD -DCHROMIUM_BUILD -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS -D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -I../.. -Igen -fno-strict-aliasing --param=ssp-buffer-size=4 -fstack-protector -funwind-tables -fPIC -pipe -pthread -fcolor-diagnostics -no-canonical-prefixes --target=arm-linux-gnueabihf -march=armv7-a -mfloat-abi=hard -mtune=generic-armv7-a -mfpu=vfpv3-d16 -mthumb -O2 -fno-ident -fdata-sections -ffunction-sections -fno-omit-frame-pointer -gdwarf-3 -g1 -fvisibility=hidden -Wheader-hygiene -Wstring-conversion -Wtautological-overlap-compare -Wall -Wno-unused-variable -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-covered-switch-default -Wno-unneeded-internal-declaration -Wno-inconsistent-missing-override -Wno-undefined-var-template -Wno-nonportable-include-path -Wno-address-of-packed-member -Wno-user-defined-warnings -fstrict-aliasing -fPIC -std=gnu++14 -nostdinc++ -isystem../../buildtools/third_party/libc++/trunk/include -isystem../../buildtools/third_party/libc++abi/trunk/include -fvisibility-inlines-hidden -fexceptions -frtti -c ../../buildtools/third_party/libc++abi/trunk/src/cxa_exception.cpp -o obj/buildtools/third_party/libc++abi/libc++abi/cxa_exception.o
../../buildtools/third_party/libc++abi/trunk/src/cxa_exception.cpp:284:21: error: unknown type name '_Unwind_Control_Block'
        static_cast<_Unwind_Control_Block*>(unwind_exception)->barrier_cache.bitpattern[0]);
                    ^
../../buildtools/third_party/libc++abi/trunk/src/cxa_exception.cpp:284:62: error: member reference base type 'void' is not a structure or union
        static_cast<_Unwind_Control_Block*>(unwind_exception)->barrier_cache.bitpattern[0]);
                                            ~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~
../../buildtools/third_party/libc++abi/trunk/src/cxa_exception.cpp:434:71: error: no member named 'barrier_cache' in '_Unwind_Exception'
        return reinterpret_cast<void*>(exception_header->unwindHeader.barrier_cache.bitpattern[0]);
                                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^