Builder here: https://uberchromegw.corp.google.com/i/chromeos/builders/nyan-chrome-pfq/builds/1192

chromeos-chrome-52.0.2713.0_rc-r1: FAILED: armv7a-cros-linux-gnueabi-g++ -B/usr/x86_64-pc-linux-gnu/armv7a-cros-linux-gnueabi/binutils-bin/2.25.51-gold -MMD -MF obj/content/common/gpu/media/content_common.v4l2_slice_video_decode_accelerator.o.d -DCONTENT_IMPLEMENTATION -DV8_DEPRECATION_WARNINGS -DCLD_VERSION=2 -D_FILE_OFFSET_BITS=64 -DGOOGLE_CHROME_BUILD -DENABLE_RLZ -DUI_COMPOSITOR_IMAGE_TRANSPORT -DUSE_AURA=1 -DUSE_ASH=1 -DUSE_PANGO=1 -DUSE_CAIRO=1 -DUSE_CRAS=1 -DUSE_DEFAULT_RENDER_THEME=1 -DUSE_LIBJPEG_TURBO=1 -DUSE_X11=1 -DIMAGE_LOADER_EXTENSION=1 -DENABLE_WEBRTC=1 -DENABLE_MEDIA_ROUTER=1 -DUSE_PROPRIETARY_CODECS -DENABLE_PEPPER_CDMS -DENABLE_NOTIFICATIONS -DENABLE_TOPCHROME_MD=1 -DENABLE_WAYLAND_SERVER=1 -DUSE_UDEV -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_PROD_WALLET_SERVICE=1 -DENABLE_PRINTING=1 -DENABLE_PRINT_PREVIEW=1 -DENABLE_SPELLCHECK=1 -DENABLE_CAPTIVE_PORTAL_DETECTION=1 -DENABLE_APP_LIST=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_V4L2_CODEC -DUSE_SECCOMP_BPF -DGL_GLEXT_PROTOTYPES -DMOJO_USE_SYSTEM_IMPL -DOPUS_FIXED_POINT -DSK_SUPPORT_GPU=1 -DSK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS -DCHROME_PNG_WRITE_SUPPORT -DPNG_USER_CONFIG -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DU_NOEXCEPT= -DU_STATIC_IMPLEMENTATION -DFEATURE_ENABLE_SSL -DFEATURE_ENABLE_VOICEMAIL -DEXPAT_RELATIVE_PATH -DGTEST_RELATIVE_PATH -DNO_MAIN_THREAD_WRAPPING -DNO_SOUND_SYSTEM -DLINUX -DWEBRTC_LINUX -DWEBRTC_POSIX -DCHROMEOS -DUSE_LIBPCI=1 -DUSE_OPENSSL=1 -DUSE_GLIB=1 -DUSE_NSS_CERTS=1 -DUSE_NSS_VERIFIER=1 -DOS_CHROMEOS=1 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -DNDEBUG -DNO_UNWIND_TABLES -DOFFICIAL_BUILD -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -D_FORTIFY_SOURCE=2 -Igen -I../../../../../../../home/chrome-bot/chrome_root/src -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/khronos -I../../../../../../../home/chrome-bot/chrome_root/src/gpu -I../../../../../../../home/chrome-bot/chrome_root/src/skia/config -Igen/angle -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/WebKit/Source -I../../../../../../../home/chrome-bot/chrome_root/src/ipc -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/opus/src/include -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/core -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/effects -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/pdf -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/gpu -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/lazy -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/pathops -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/pipe -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/ports -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/skia/include/utils -I../../../../../../../home/chrome-bot/chrome_root/src/skia/ext -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/WebKit -I../../../../../../../home/chrome-bot/chrome_root/src/v8/include -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/libpng -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/zlib -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/libwebp -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/ots/include -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/qcms/src -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/iccjpeg -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/libjpeg_turbo -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/WebKit -Igen/third_party/WebKit -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/boringssl/src/include -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/icu/source/common -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/icu/source/i18n -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/mesa/src/include -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/webrtc_overrides -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/libjingle/overrides -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/libjingle/source -I../../../../../../../home/chrome-bot/chrome_root/src/testing/gtest/include -I../../../../../../../home/chrome-bot/chrome_root/src/third_party -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/libyuv/include -I../../../../../../../home/chrome-bot/chrome_root/src/third_party/libyuv -Werror -pthread -fno-strict-aliasing -Wall -Wno-extra -Wno-unused-parameter -Wno-missing-field-initializers -fvisibility=hidden -pipe -fPIC -g -Wno-unused-local-typedefs -pthread -I/build/nyan/usr/include/glib-2.0 -I/build/nyan/usr/lib/glib-2.0/include -I/build/nyan/usr/include/dbus-1.0 -I/build/nyan/usr/lib/dbus-1.0/include -pthread -I/build/nyan/usr/include/pango-1.0 -I/build/nyan/usr/include/cairo -I/build/nyan/usr/include/glib-2.0 -I/build/nyan/usr/lib/glib-2.0/include -I/build/nyan/usr/include/pixman-1 -I/build/nyan/build/nyan/usr/include/freetype2 -I/build/nyan/usr/include/freetype2 -I/build/nyan/usr/include/libpng12 -march=armv7-a -mtune=generic-armv7-a -mfpu=neon -mfloat-abi=hard -mthumb --sysroot=/build/nyan -O2 -fno-ident -fdata-sections -ffunction-sections -fno-unwind-tables -fno-asynchronous-unwind-tables -g1 -pipe -march=armv7-a -mtune=cortex-a15 -mfpu=neon -mfloat-abi=hard -D__google_stl_debug_vector=1 -fno-exceptions -fno-rtti -fno-threadsafe-statics -fvisibility-inlines-hidden -Wno-abi -std=gnu++11 -Wno-narrowing -Wno-literal-suffix  -c ../../../../../../../home/chrome-bot/chrome_root/src/content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc -o obj/content/common/gpu/media/content_common.v4l2_slice_video_decode_accelerator.o
chromeos-chrome-52.0.2713.0_rc-r1: ../../../../../../../home/chrome-bot/chrome_root/src/content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc: In member function 'virtual void content::V4L2SliceVideoDecodeAccelerator::ImportBufferForPicture(int32_t, const std::vector<gfx::GpuMemoryBufferHandle>&)':
chromeos-chrome-52.0.2713.0_rc-r1: ../../../../../../../home/chrome-bot/chrome_root/src/content/common/gpu/media/v4l2_slice_video_decode_accelerator.cc:1670:20: error: unused variable 'handle' [-Werror=unused-variable]
chromeos-chrome-52.0.2713.0_rc-r1:    for (const auto& handle : gpu_memory_buffer_handles) {
chromeos-chrome-52.0.2713.0_rc-r1:                     ^
chromeos-chrome-52.0.2713.0_rc-r1: cc1plus: all warnings being treated as errors

jbauman, I saw you were working on that file before, it seems to be breaking some ChromeOS builders. Can you look into this?