Ran this command:

  % git pull; gclient sync --jobs 32; gn gen out/Release; ninja -C out/Release blink_tests content_shell -j 400

with the following gn args:

  is_debug = false
  use_goma = true
  enable_nacl = true
  is_asan = true

at revision 496591.

Log:

[14406/14416] ACTION //tools/v8_context_snapshot:generate_v8_context_snapshot(//build/toolchain/linux:clang_x64)
FAILED: v8_context_snapshot.bin
python ../../tools/v8_context_snapshot/run.py ./v8_context_snapshot_generator --output_file=v8_context_snapshot.bin

=================================================================
==17916==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 1232 byte(s) in 2 object(s) allocated from:
    #0 0x4f6f12  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x4f6f12)
    #1 0x10ac9f3  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10ac9f3)
    #2 0x10b2d79  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10b2d79)
    #3 0x10b3180  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10b3180)
    #4 0x281c0a6  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x281c0a6)
    #5 0x28a8adc  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a8adc)
    #6 0x28a9c30  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a9c30)
    #7 0x28a7f95  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a7f95)
    #8 0x294aad0  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x294aad0)
    #9 0x28be934  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28be934)
    #10 0x7f56f3e97183  (/lib/x86_64-linux-gnu/libpthread.so.0+0x8183)

Direct leak of 1232 byte(s) in 2 object(s) allocated from:
    #0 0x4f6f12  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x4f6f12)
    #1 0x10ac9f3  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10ac9f3)
    #2 0x10186e7  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10186e7)
    #3 0x102f054  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x102f054)
    #4 0x1032e62  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x1032e62)
    #5 0xff81a8  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff81a8)
    #6 0xff565f  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff565f)
    #7 0xff5135  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff5135)
    #8 0x103474f  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x103474f)
    #9 0xf7ada4  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xf7ada4)
    #10 0x281c0a6  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x281c0a6)
    #11 0x28a8adc  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a8adc)
    #12 0x28a9c30  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a9c30)
    #13 0x28a7f95  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a7f95)
    #14 0x294aad0  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x294aad0)
    #15 0x28be934  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28be934)
    #16 0x7f56f3e97183  (/lib/x86_64-linux-gnu/libpthread.so.0+0x8183)

Direct leak of 616 byte(s) in 1 object(s) allocated from:
    #0 0x4f6f12  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x4f6f12)
    #1 0x10ac9f3  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10ac9f3)
    #2 0x10186e7  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10186e7)
    #3 0x10303ed  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10303ed)
    #4 0x1032e62  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x1032e62)
    #5 0x101acb0  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x101acb0)
    #6 0xff5ebb  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff5ebb)
    #7 0xff55a7  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff55a7)
    #8 0xff5135  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff5135)
    #9 0x103474f  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x103474f)
    #10 0xf7ada4  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xf7ada4)
    #11 0x281c0a6  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x281c0a6)
    #12 0x28a8adc  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a8adc)
    #13 0x28a9c30  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a9c30)
    #14 0x28a7f95  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28a7f95)
    #15 0x294aad0  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x294aad0)
    #16 0x28be934  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x28be934)
    #17 0x7f56f3e97183  (/lib/x86_64-linux-gnu/libpthread.so.0+0x8183)

Direct leak of 616 byte(s) in 1 object(s) allocated from:
    #0 0x4f6f12  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x4f6f12)
    #1 0x10ac9f3  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10ac9f3)
    #2 0x10186e7  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x10186e7)
    #3 0x102f054  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x102f054)
    #4 0x1032e62  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x1032e62)
    #5 0xff81a8  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff81a8)
    #6 0xff565f  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff565f)
    #7 0xff5135  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xff5135)
    #8 0x103474f  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x103474f)
    #9 0xf7ada4  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xf7ada4)
    #10 0xf4a57d  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xf4a57d)
    #11 0xffc85c  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xffc85c)
    #12 0xffbd55  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xffbd55)
    #13 0xfd2d8e  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xfd2d8e)
    #14 0xfcb7ca  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xfcb7ca)
    #15 0xf41966  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xf41966)
    #16 0xf3c802  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xf3c802)
    #17 0xf3a2ff  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xf3a2ff)
    #18 0xf3b1c4  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0xf3b1c4)
    #19 0x5185f9  (/media/ssd/chromium/src/out/Release/v8_context_snapshot_generator+0x5185f9)

...snip...

SUMMARY: AddressSanitizer: 42148 byte(s) leaked in 146 allocation(s).
[14408/14416] CXX obj/third_party/WebKit/Source/platform/heap/blink_heap_unittests/HeapTest.o
ninja: build stopped: subcommand failed.