Filed by sheriff-o-matic@appspot.gserviceaccount.com on behalf of rogerm@chromium.org

crashpad bootstrap failing for browser_tests on chromium.mac/Mac10.{11, 12} Tests

Builders failed on: 
- Mac10.11 Tests: 
  https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac10.11%20Tests

- Mac10.12 Tests: 
  https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac10.12%20Tests

Error messages look like:

[0613/095141.842123:ERROR:mach_extensions.cc(68)] bootstrap_check_in org.chromium.crashpad.child_port_handshake.20121.430428.ZBXCTOTRIWXTXOOY: unknown error code (141)
[0613/095141.842242:FATAL:child_port_handshake.cc(111)] Check failed: server_port.is_valid().
0   crashpad_handler                    0x00000001025e158c base::debug::StackTrace::StackTrace(unsigned long) + 28
1   crashpad_handler                    0x00000001025ce3c1 logging::LogMessage::~LogMessage() + 225
2   crashpad_handler                    0x00000001025eb274 crashpad::ChildPortHandshake::RunServerForFD(base::ScopedGeneric<int, base::internal::ScopedFDCloseTraits>, crashpad::ChildPortHandshake::PortRightType) + 516
3   crashpad_handler                    0x00000001025bd266 crashpad::HandlerMain(int, char**, std::__1::vector<std::__1::unique_ptr<crashpad::UserStreamDataSource, std::__1::default_delete<crashpad::UserStreamDataSource> >, std::__1::allocator<std::__1::unique_ptr<crashpad::UserStreamDataSource, std::__1::default_delete<crashpad::UserStreamDataSource> > > > const*) + 4790
4   libdyld.dylib                       0x00007fff94c615ad start + 1
[0613/095141.842710:ERROR:file_io.cc(89)] ReadExactly: expected 4, observed 0