UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.18 Safari/537.36

Steps to reproduce the problem:
1. download dev channel 51.0.2679.0
2. use gyp_chromium for build
3. build

What is the expected behavior?
build OK

What went wrong?
fail build

Did this work before? Yes in 50.0.2661.18

Chrome version: 50.0.2661.18  Channel: n/a
OS Version: 
Flash Version: Shockwave Flash 21.0 r0

regression in this commit: https://codereview.chromium.org/1758573002

[17767/19398] /tmp/makepkg/chromium-dev/src/chromium-51.0.2679.0/third_party/llvm-build/Release+Asserts/bin/clang++ -Qunused-arguments -MMD -MF obj/chrome/browser/ui/webui/omnibox/browser_ui.omnibox_ui_handler.o.d -DV8_DEPRECATION_WARNINGS -DCLD_VERSION=2 -D_FILE_OFFSET_BITS=64 -DCHROMIUM_BUILD -DCR_CLANG_REVISION=263324-1 -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_PANGO=1 -DUSE_CAIRO=1 -DUSE_DEFAULT_RENDER_THEME=1 -DUSE_LIBJPEG_TURBO=1 -DUSE_X11=1 -DUSE_CLIPBOARD_AURAX11=1 -DENABLE_WEBRTC=1 -DENABLE_MEDIA_ROUTER=1 -DUSE_PROPRIETARY_CODECS -DENABLE_PEPPER_CDMS -DENABLE_CONFIGURATION_POLICY -DENABLE_NOTIFICATIONS -DENABLE_TOPCHROME_MD=1 -DUSE_UDEV -DFIELDTRIAL_TESTING_ENABLED -DENABLE_TASK_MANAGER=1 -DENABLE_EXTENSIONS=1 -DENABLE_PDF=1 -DENABLE_PLUGINS=1 -DENABLE_SESSION_SERVICE=1 -DENABLE_THEMES=1 -DENABLE_AUTOFILL_DIALOG=1 -DENABLE_PRINTING=1 -DENABLE_BASIC_PRINTING=1 -DENABLE_PRINT_PREVIEW=1 -DENABLE_SPELLCHECK=1 -DENABLE_CAPTIVE_PORTAL_DETECTION=1 -DENABLE_APP_LIST=1 -DENABLE_SETTINGS_APP=1 -DENABLE_SUPERVISED_USERS=1 -DENABLE_MDNS=1 -DENABLE_SERVICE_DISCOVERY=1 -DENABLE_HANGOUT_SERVICES_EXTENSION=1 -DV8_USE_EXTERNAL_STARTUP_DATA -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DUSE_SYSTEM_MINIZIP -DGL_GLEXT_PROTOTYPES -DMOJO_USE_SYSTEM_IMPL -DTOOLKIT_VIEWS=1 -DPROTOBUF_USE_DLLS -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DSK_SUPPORT_GPU=1 -DSK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DU_STATIC_IMPLEMENTATION -DUSE_SYSTEM_ZLIB -DUSE_CUPS '-DI18N_ADDRESS_VALIDATION_DATA_URL="https://i18napis.appspot.com/ssl-aggregate-address/"' -DI18N_ADDRESSINPUT_USE_BASICTYPES_OVERRIDE=1 -DUSE_LIBPCI=1 -DUSE_OPENSSL=1 -DUSE_GLIB=1 -DUSE_NSS_CERTS=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -Igen/shim_headers/libflac/target -Igen/shim_headers/libvpx/target -Igen/shim_headers/snappy/target -Igen/shim_headers/libpng/target -Igen/shim_headers/harfbuzz-ng/target -Igen/shim_headers/zlib/target -Igen -I../.. -Iobj/chrome/browser_ui.gen -Iobj/chrome/browser_ui.gen/chrome -I../../skia/config -I../../third_party/khronos -I../../gpu -Igen/angle -I../../third_party/WebKit/Source -Igen/chrome -Igen/protoc_out -I../../third_party/protobuf -I../../third_party/protobuf/src -I../../third_party/dom_distiller_js/dist/proto_gen -Igen/components -Igen/components/strings -I../../third_party/WebKit -I../../third_party/skia/include/core -I../../third_party/skia/include/effects -I../../third_party/skia/include/pdf -I../../third_party/skia/include/gpu -I../../third_party/skia/include/lazy -I../../third_party/skia/include/pathops -I../../third_party/skia/include/pipe -I../../third_party/skia/include/ports -I../../third_party/skia/include/utils -I../../skia/ext -I../../third_party/cacheinvalidation/overrides -I../../third_party/cacheinvalidation/src -I../../third_party/cacheinvalidation/google/cacheinvalidation -I../../third_party/icu/source/i18n -I../../third_party/icu/source/common -Igen/ui/resources -Igen/content/app/resources/ -I../../third_party/opus/src/include -I../../third_party/leveldatabase/src/include -I../../third_party/leveldatabase/src -I../../third_party/leveldatabase -I../../third_party/re2/src -I../../v8/include -Igen/policy -Igen/ash/resources -Igen/ui/keyboard -I../../third_party/mesa/src/include -Igen/ui/views/resources -I../../third_party/libaddressinput/chromium/override -I../../third_party/libaddressinput/src/cpp/include -Igen/third_party/libaddressinput/ -I../../third_party/libusb/src/libusb -fstack-protector --param=ssp-buffer-size=4  -pthread -fno-strict-aliasing -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -fvisibility=hidden -pipe -fPIC -Xclang -load -Xclang /tmp/makepkg/chromium-dev/src/chromium-51.0.2679.0/third_party/llvm-build/Release+Asserts/lib/libFindBadConstructs.so -Xclang -add-plugin -Xclang find-bad-constructs -Xclang -plugin-arg-find-bad-constructs -Xclang check-templates -Xclang -plugin-arg-find-bad-constructs -Xclang follow-macro-expansion -fcolor-diagnostics -Wheader-hygiene -Wno-char-subscripts -Wno-unneeded-internal-declaration -Wno-covered-switch-default -Wstring-conversion -Wno-c++11-narrowing -Wno-deprecated-register -Wno-inconsistent-missing-override -Wno-shift-negative-value -Wno-nonnull -Wexit-time-destructors -pthread -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/freetype2 -I/usr/include/harfbuzz -I/usr/include/libdrm -I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng16 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -pthread -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/nss -I/usr/include/nspr -Wno-header-guard -I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -m64 -march=x86-64 -O2 -fno-ident -fdata-sections -ffunction-sections -funwind-tables -march=native -O2 -pipe -fstack-protector-strong -D_FORTIFY_SOURCE=2 -fno-exceptions -fno-rtti -fno-threadsafe-statics -fvisibility-inlines-hidden -std=gnu++11  -c ../../chrome/browser/ui/webui/omnibox/omnibox_ui_handler.cc -o obj/chrome/browser/ui/webui/omnibox/browser_ui.omnibox_ui_handler.o
FAILED: /tmp/makepkg/chromium-dev/src/chromium-51.0.2679.0/third_party/llvm-build/Release+Asserts/bin/clang++ -Qunused-arguments -MMD -MF obj/chrome/browser/ui/webui/engagement/browser_ui.site_engagement_ui.o.d -DV8_DEPRECATION_WARNINGS -DCLD_VERSION=2 -D_FILE_OFFSET_BITS=64 -DCHROMIUM_BUILD -DCR_CLANG_REVISION=263324-1 -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_PANGO=1 -DUSE_CAIRO=1 -DUSE_DEFAULT_RENDER_THEME=1 -DUSE_LIBJPEG_TURBO=1 -DUSE_X11=1 -DUSE_CLIPBOARD_AURAX11=1 -DENABLE_WEBRTC=1 -DENABLE_MEDIA_ROUTER=1 -DUSE_PROPRIETARY_CODECS -DENABLE_PEPPER_CDMS -DENABLE_CONFIGURATION_POLICY -DENABLE_NOTIFICATIONS -DENABLE_TOPCHROME_MD=1 -DUSE_UDEV -DFIELDTRIAL_TESTING_ENABLED -DENABLE_TASK_MANAGER=1 -DENABLE_EXTENSIONS=1 -DENABLE_PDF=1 -DENABLE_PLUGINS=1 -DENABLE_SESSION_SERVICE=1 -DENABLE_THEMES=1 -DENABLE_AUTOFILL_DIALOG=1 -DENABLE_PRINTING=1 -DENABLE_BASIC_PRINTING=1 -DENABLE_PRINT_PREVIEW=1 -DENABLE_SPELLCHECK=1 -DENABLE_CAPTIVE_PORTAL_DETECTION=1 -DENABLE_APP_LIST=1 -DENABLE_SETTINGS_APP=1 -DENABLE_SUPERVISED_USERS=1 -DENABLE_MDNS=1 -DENABLE_SERVICE_DISCOVERY=1 -DENABLE_HANGOUT_SERVICES_EXTENSION=1 -DV8_USE_EXTERNAL_STARTUP_DATA -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DUSE_SYSTEM_MINIZIP -DGL_GLEXT_PROTOTYPES -DMOJO_USE_SYSTEM_IMPL -DTOOLKIT_VIEWS=1 -DPROTOBUF_USE_DLLS -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DSK_SUPPORT_GPU=1 -DSK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DU_STATIC_IMPLEMENTATION -DUSE_SYSTEM_ZLIB -DUSE_CUPS '-DI18N_ADDRESS_VALIDATION_DATA_URL="https://i18napis.appspot.com/ssl-aggregate-address/"' -DI18N_ADDRESSINPUT_USE_BASICTYPES_OVERRIDE=1 -DUSE_LIBPCI=1 -DUSE_OPENSSL=1 -DUSE_GLIB=1 -DUSE_NSS_CERTS=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -Igen/shim_headers/libflac/target -Igen/shim_headers/libvpx/target -Igen/shim_headers/snappy/target -Igen/shim_headers/libpng/target -Igen/shim_headers/harfbuzz-ng/target -Igen/shim_headers/zlib/target -Igen -I../.. -Iobj/chrome/browser_ui.gen -Iobj/chrome/browser_ui.gen/chrome -I../../skia/config -I../../third_party/khronos -I../../gpu -Igen/angle -I../../third_party/WebKit/Source -Igen/chrome -Igen/protoc_out -I../../third_party/protobuf -I../../third_party/protobuf/src -I../../third_party/dom_distiller_js/dist/proto_gen -Igen/components -Igen/components/strings -I../../third_party/WebKit -I../../third_party/skia/include/core -I../../third_party/skia/include/effects -I../../third_party/skia/include/pdf -I../../third_party/skia/include/gpu -I../../third_party/skia/include/lazy -I../../third_party/skia/include/pathops -I../../third_party/skia/include/pipe -I../../third_party/skia/include/ports -I../../third_party/skia/include/utils -I../../skia/ext -I../../third_party/cacheinvalidation/overrides -I../../third_party/cacheinvalidation/src -I../../third_party/cacheinvalidation/google/cacheinvalidation -I../../third_party/icu/source/i18n -I../../third_party/icu/source/common -Igen/ui/resources -Igen/content/app/resources/ -I../../third_party/opus/src/include -I../../third_party/leveldatabase/src/include -I../../third_party/leveldatabase/src -I../../third_party/leveldatabase -I../../third_party/re2/src -I../../v8/include -Igen/policy -Igen/ash/resources -Igen/ui/keyboard -I../../third_party/mesa/src/include -Igen/ui/views/resources -I../../third_party/libaddressinput/chromium/override -I../../third_party/libaddressinput/src/cpp/include -Igen/third_party/libaddressinput/ -I../../third_party/libusb/src/libusb -fstack-protector --param=ssp-buffer-size=4  -pthread -fno-strict-aliasing -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -fvisibility=hidden -pipe -fPIC -Xclang -load -Xclang /tmp/makepkg/chromium-dev/src/chromium-51.0.2679.0/third_party/llvm-build/Release+Asserts/lib/libFindBadConstructs.so -Xclang -add-plugin -Xclang find-bad-constructs -Xclang -plugin-arg-find-bad-constructs -Xclang check-templates -Xclang -plugin-arg-find-bad-constructs -Xclang follow-macro-expansion -fcolor-diagnostics -Wheader-hygiene -Wno-char-subscripts -Wno-unneeded-internal-declaration -Wno-covered-switch-default -Wstring-conversion -Wno-c++11-narrowing -Wno-deprecated-register -Wno-inconsistent-missing-override -Wno-shift-negative-value -Wno-nonnull -Wexit-time-destructors -pthread -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/freetype2 -I/usr/include/harfbuzz -I/usr/include/libdrm -I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng16 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -pthread -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/nss -I/usr/include/nspr -Wno-header-guard -I/usr/include/dbus-1.0 -I/usr/lib/dbus-1.0/include -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -m64 -march=x86-64 -O2 -fno-ident -fdata-sections -ffunction-sections -funwind-tables -march=native -O2 -pipe -fstack-protector-strong -D_FORTIFY_SOURCE=2 -fno-exceptions -fno-rtti -fno-threadsafe-statics -fvisibility-inlines-hidden -std=gnu++11  -c ../../chrome/browser/ui/webui/engagement/site_engagement_ui.cc -o obj/chrome/browser/ui/webui/engagement/browser_ui.site_engagement_ui.o
../../chrome/browser/ui/webui/engagement/site_engagement_ui.cc:58:52: error: use of undeclared identifier 'isnan'
        score > SiteEngagementScore::kMaxPoints || isnan(score)) {
                                                   ^
1 error generated.
ninja: build stopped: subcommand failed.

gyp options:

'-Dclang_use_chrome_plugins=1'
'-Dhost_clang=1'
'-Dclang=1'
'-Ddisable_glibc=1'
'-Ddisable_fatal_linker_warnings=1'
'-Denable_sql_database=0'
'-Denable_hidpi=1'
'-Denable_touch_ui=1'
'-Denable_webrtc=1'
'-Denable_widevine=1'
'-Denable_pepper_cdms=1'
'-Denable_hotwording=0'
'-Denable_hangout_services_extension=1'
'-Dffmpeg_branding=ChromeOS'
'-Dlibspeechd_h_prefix=speech-dispatcher/'
'-Dlinux_link_gnome_keyring=0'
'-Dlinux_link_gsettings=0'
'-Dlinux_link_kerberos=1'
'-Dlinux_link_libbrlapi=1'
'-Dlinux_link_libpci=1'
'-Dlinux_link_libspeechd=1'
'-Dlinux_link_pulseaudio=1'
'-Dlinux_strip_binary=1'
'-Dlinux_use_bundled_binutils=0'
'-Dlinux_use_bundled_gold=0'
'-Dlinux_use_gold_flags=0'
'-Dlogging_like_official_build=1'
'-Dno_strict_aliasing=1'
'-Dproprietary_codecs=1'
'-Dpython_ver=2.7'
'-Dremove_webcore_debug_symbols=1'
'-Dtarget_arch=x64'
'-Dusb_ids_path=/usr/share/hwdata/usb.ids'
'-Duse_gconf=0'
'-Duse_gio=0'
'-Duse_gnome_keyring=0'
'-Duse_gtk3=1'
'-Duse_pulseaudio=1
'-Duse_sysroot=0'
'-Dwerror='
'-Duse_system_expat=1'
'-Duse_system_ffmpeg=1'
'-Duse_system_flac=1'
'-Duse_system_fontconfig=1'
'-Duse_system_harfbuzz=1'
'-Duse_system_icu=1'
'-Duse_system_jsoncpp=1'
'-Duse_system_libevent=0'
'-Duse_system_libexif=1'
'-Duse_system_libjpeg=1'
'-Duse_system_libpng=1'
'-Duse_system_libsrtp=0'
'-Duse_system_libusb=0'
'-Duse_system_libvpx=1'
'-Duse_system_libwebp=1'
'-Duse_system_libxml=1'
'-Duse_system_libxnvctrl=0'
'-Duse_system_libxslt=1'
'-Duse_system_minizip=1'
'-Duse_system_nspr=1'
'-Duse_system_openssl=0'
'-Duse_system_opus=0'
'-Duse_system_protobuf=0'
'-Duse_system_re2=0'
'-Duse_system_snappy=1'
'-Duse_system_speex=1'
'-Duse_system_sqlite=0'
'-Duse_system_ssl=0'
'-Duse_system_v8=0'
'-Duse_system_yasm=1'
'-Duse_system_xdg_utils=1'
'-Duse_system_zlib=1'