This is different from the crash in https://chromium-swarm.appspot.com/task?id=3c7be7b364773410&refresh=10&show_raw=1, but uses the same test flags.

As of f299db8a1,

$ cat out/asan/args.gn 
is_component_build = true
is_asan = true
is_lsan = true
is_debug = false
enable_nacl = false
use_goma = true

$ ninja -C out/asan/ browser_tests
$ ASAN_OPTIONS="detect_odr_violation=0
detect_leaks=1 symbolize=1 external_symbolizer_path=$PWD/third_party/llvm-build/Release+Asserts/bin/llvm-symbolizer" out/asan/browser_tests --brave-new-test-launcher --test-launcher-retry-limit=0 --test-launcher-bot-mode --enable-features=Mus  --gtest_filter=MediaRouterIntegrationOneUANoReceiverBrowserTest.ReconnectSessionSameTab |tools/valgrind/asan/asan_symbolize.py

Gives:

...

[116496:116496:0326/141754.302680:ERROR:gl_surface_egl.cc(895)] Error trying to initialize the native window.                                                                                                      
[116496:116496:0326/141754.302798:ERROR:gles2_command_buffer_stub.cc(226)] ContextResult::kFatalFailure: Failed to create surface.
[116496:116496:0326/141754.303418:WARNING:x11_util.cc(1362)] X error received: serial 156, error_code 3 (BadWindow), request_code 3, minor_code 0 (Unknown)
[116405:116405:0326/141754.351548:ERROR:gpu_process_transport_factory.cc(1011)] Lost UI shared context.
[116405:116405:0326/141754.351924:ERROR:software_output_device_x11.cc(25)] XGetWindowAttributes failed for window 1
[116405:116450:0326/141754.374903:ERROR:instance.cc(49)] Unable to locate service manifest for ui
[116405:116450:0326/141754.374999:ERROR:service_manager.cc(930)] Failed to resolve service name: ui
[116405:116405:0326/141754.387650:WARNING:x11_util.cc(1362)] X error received: serial 184, error_code 9 (BadDrawable (invalid Pixmap or Window parameter)), request_code 55, minor_code 0 (X_CreateGC)
[116405:116405:0326/141754.387793:WARNING:x11_util.cc(1362)] X error received: serial 185, error_code 3 (BadWindow (invalid Window parameter)), request_code 3, minor_code 0 (X_GetWindowAttributes)
BrowserTestBase received signal: Segmentation fault. Backtrace:
    #0 0x00000297cbc1 in __interceptor_backtrace /b/build/slave/linux_upload_clang/build/src/third_party/llvm/compiler-rt/lib/asan/../sanitizer_common/sanitizer_common_interceptors.inc:3980:13
    #1 0x7feaceaae24c in base::debug::StackTrace::StackTrace(unsigned long) ../../base/debug/stack_trace_posix.cc:808:41
    #2 0x000008d00186 in content::(anonymous namespace)::DumpStackTraceSignalHandler(int) ../../content/public/test/browser_test_base.cc:86:5
    #3 0x7feaa8fe8030 in killpg ??:?
    #4 0x7feaa8fe8030 in ?? ??:0
    #5 0x7feaaa2ebb12 in XRenderCreatePicture ??:0:0                                                     
    #6 0x7feaae97a6a3 in viz::SoftwareOutputDeviceX11::EndPaint() ../../components/viz/service/display_embedder/software_output_device_x11.cc:86:9
    #7 0x7feaae859768 in viz::SoftwareRenderer::FinishDrawingFrame() ../../components/viz/service/display/software_renderer.cc:66:19
    #8 0x7feaae7aa2c9 in viz::DirectRenderer::DrawFrame(std::__1::vector<std::__1::unique_ptr<viz::RenderPass, std::__1::default_delete<viz::RenderPass> >, std::__1::allocator<std::__1::unique_ptr<viz::RenderPass, std::__1::default_delete<viz::RenderPass> > > >*, float, gfx::Size const&) ../../components/viz/service/display/direct_renderer.cc:334:3
    #9 0x7feaae7bb1ba in viz::Display::DrawAndSwap() ../../components/viz/service/display/display.cc:356:16
    #10 0x7feaae7ca96c in viz::DisplayScheduler::DrawAndSwap() ../../components/viz/service/display/display_scheduler.cc:213:27
    #11 0x7feaae7c6aab in viz::DisplayScheduler::OnBeginFrameDeadline() ../../components/viz/service/display/display_scheduler.cc:503:19
    #12 0x7feaceab0471 in Run ../../base/callback.h:95:12


Removing --enable-features=Mus makes the crash go away.