Bot:
https://build.chromium.org/p/chromium.webrtc.fyi/builders/Mac%20Builder%20%28dbg%29?numbuilds=200

Failure:
[13154/13198] LINK ./unittests
FAILED: unittests 
export DEVELOPER_DIR=/b/c/b/Mac_Builder__dbg_/src/build/mac_files/Xcode.app;  TOOL_VERSION=1502996840 ../../build/toolchain/mac/linker_driver.py ../../third_party/llvm-build/Release+Asserts/bin/clang++  -stdlib=libc++ -arch x86_64 -Werror -isysroot ../../build/mac_files/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk -mmacosx-version-min=10.9.0 -Wl,-ObjC -Wl,-rpath,@loader_path/. -Wl,-rpath,@loader_path/../../.. -Wl,-pie -Wl,-dead_strip -o "./unittests" -Wl,-filelist,"./unittests.rsp" ./libv8_for_testing.dylib ./libv8_libbase.dylib ./libv8_libplatform.dylib ./libicui18n.dylib ./libicuuc.dylib 
Undefined symbols for architecture x86_64:
  "v8::internal::GetRandomMmapAddr()", referenced from:
      v8::internal::HeapTest_ASLR_Test::TestBody() in heap-unittest.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Traceback (most recent call last):
  File "../../build/toolchain/mac/linker_driver.py", line 229, in <module>
    Main(sys.argv)
  File "../../build/toolchain/mac/linker_driver.py", line 79, in Main
    subprocess.check_call(compiler_driver_args)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 540, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['../../third_party/llvm-build/Release+Asserts/bin/clang++', '-stdlib=libc++', '-arch', 'x86_64', '-Werror', '-isysroot', '../../build/mac_files/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk', '-mmacosx-version-min=10.9.0', '-Wl,-ObjC', '-Wl,-rpath,@loader_path/.', '-Wl,-rpath,@loader_path/../../..', '-Wl,-pie', '-Wl,-dead_strip', '-o', './unittests', '-Wl,-filelist,./unittests.rsp', './libv8_for_testing.dylib', './libv8_libbase.dylib', './libv8_libplatform.dylib', './libicui18n.dylib', './libicuuc.dylib']' returned non-zero exit status 1

Change range:
https://chromium.googlesource.com/chromium/src/+log/377e71a05bd7d53c33948f0aedfbff859ef11b0f..d5ebd4bfd14f9797c64251bf4ec7aa4147ef7839?pretty=oneline&n=10000

The cause should be the V8 roll
https://chromium.googlesource.com/chromium/src/+/f244b41c3d6c3a52624b5325bf66d9c6a56d08df,
and in particular the change
https://chromium.googlesource.com/v8/v8/+/d607f1e72d082c9c4dac4d6359858e20a10f16b6

It doesn't happen on any other WebRTC bot.

phoglund@ and V8 triager, please have a look.