Per user report [1], ASAN was recently broken in GN. I reproduced that:

$ gn gen //out/gn '--args=is_asan=true is_debug=false' --check
$ ninja -C out/gn-asan gdb_rsp_unittest
...
FAILED: gdb_rsp_unittest 
../../third_party/llvm-build/Release+Asserts/bin/clang++ -Wl,--fatal-warnings -fPIC -Wl,-z,noexecstack -Wl,-z,now -Wl,-z,relro -B../../third_party/binutils/Linux_x64/Release/bin -fuse-ld=gold -pthread -m64 -Wl,
-O1 -Wl,--gc-sections --sysroot=../../build/linux/debian_wheezy_amd64-sysroot  -fsanitize=address -Wl,-rpath-link=../gn-asan -Wl,--disable-new-dtags -Wl,-rpath=\$ORIGIN/. -Wl,-rpath-link=. -o "./gdb_rsp_unittes
t" -Wl,--start-group @"./gdb_rsp_unittest.rsp"  -Wl,--end-group  -ldl -lrt 
../../native_client/src/trusted/debug_stub/packet_test.cc:98: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()'
../../buildtools/third_party/libc++/trunk/include/string:3833: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::compare(unsigned long, unsign
ed long, char const*, unsigned long) const'
../../buildtools/third_party/libc++/trunk/include/string:3833: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::compare(unsigned long, unsign
ed long, char const*, unsigned long) const'
../../native_client/src/trusted/debug_stub/session_test.cc:268: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()'
../../buildtools/third_party/libc++/trunk/include/vector:962: error: undefined reference to 'std::__1::__vector_base_common<true>::__throw_length_error() const'
../../buildtools/third_party/libc++/trunk/include/string:2027: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(char const*, unsigned 
long)'
../../native_client/src/trusted/debug_stub/util_test.cc:73: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()'
../../native_client/src/trusted/debug_stub/util_test.cc:73: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()'
../../buildtools/third_party/libc++/trunk/include/string:2027: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(char const*, unsigned 
long)'
../../buildtools/third_party/libc++/trunk/include/string:2027: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(char const*, unsigned 
long)'
../../buildtools/third_party/libc++/trunk/include/string:1398: error: undefined reference to 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::assign(char const*)'
../../buildtools/third_party/libc++/trunk/include/ios:673: error: undefined reference to 'std::__1::ios_base::init(void*)'
...

The ASAN bot is green, but it's based on GYP:
https://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20Builder

We need to fix ASAN in GN, and probably convert the bot to GN.

1. https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/EvDzuMBAaIk