UserAgent: Mozilla/5.0 (X11; CrOS x86_64 11151.59.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.94 Safari/537.36
Platform: 11151.59.0

Example URL:

Steps to reproduce the problem:
1. Dock Chromebook to a docking station (plugable) prior to updating to version 71.0.3578.94
2. Check for updates and restart machine to apply update
3. USB audio no longer available as an output

What is the expected behavior?
USB audio output from docking station to be an option after the update

What went wrong?
USB audio output is removed from the available output options

Did this work before? N/A 

Is it a problem with Flash or HTML5? N/A

Does this work in other browsers? N/A

Chrome version: 71.0.3578.94  Channel: n/a
OS Version: 11151.59.0
Flash Version: 32.0.0.101 

Contents of chrome://gpu: 

Graphics Feature Status
Canvas: Hardware accelerated
Flash: Hardware accelerated
Flash Stage3D: Hardware accelerated
Flash Stage3D Baseline profile: Hardware accelerated
Compositing: Hardware accelerated
Multiple Raster Threads: Disabled
Native GpuMemoryBuffers: Hardware accelerated
Out-of-process Rasterization: Disabled
Hardware Protected Video Decode: Unavailable
Rasterization: Hardware accelerated
Skia Deferred Display List: Disabled
Skia Renderer: Disabled
Surface Control: Disabled
Surface Synchronization: Enabled
Video Decode: Hardware accelerated
Viz Service Display Compositor: Disabled
WebGL: Hardware accelerated
WebGL2: Hardware accelerated
Driver Bug Workarounds
clear_uniforms_before_first_program_use
count_all_in_varyings_packing
decode_encode_srgb_for_generatemipmap
disable_discard_framebuffer
disable_framebuffer_cmaa
msaa_is_slow
rely_on_implicit_sync_for_swap_buffers
scalarize_vec_and_mat_constructor_args
disabled_extension_GL_KHR_blend_equation_advanced
disabled_extension_GL_KHR_blend_equation_advanced_coherent
Problems Detected
Protected video decoding with swap chain is for Windows and Intel only
Disabled Features: protected_video_decode
Framebuffer discarding causes jumpy scrolling on Mali drivers: 301988
Applied Workarounds: disable_discard_framebuffer
Clear uniforms before first program use on all platforms: 124764, 349137
Applied Workarounds: clear_uniforms_before_first_program_use
Mesa drivers in ChromeOS handle varyings without static use incorrectly: 333885
Applied Workarounds: count_all_in_varyings_packing
Always rewrite vec/mat constructors to be consistent: 398694
Applied Workarounds: scalarize_vec_and_mat_constructor_args
On Intel GPUs MSAA performance is not acceptable for GPU rasterization: 527565
Applied Workarounds: msaa_is_slow
Use GL_INTEL_framebuffer_CMAA on ChromeOS: 535198
Applied Workarounds: disable_framebuffer_cmaa
Disable KHR_blend_equation_advanced until cc shaders are updated: 661715
Applied Workarounds: disable(GL_KHR_blend_equation_advanced), disable(GL_KHR_blend_equation_advanced_coherent)
Decode and Encode before generateMipmap for srgb format textures on Chromeos Intel: 634519
Applied Workarounds: decode_encode_srgb_for_generatemipmap
Avoid waiting on a egl fence before pageflipping and rely on implicit sync.: 721463
Applied Workarounds: rely_on_implicit_sync_for_swap_buffers
Raster is using a single thread.
Disabled Features: multiple_raster_threads
Viz service display compositor is not enabled by default.
Disabled Features: viz_display_compositor
Skia renderer is not used by default.
Disabled Features: skia_renderer
Skia deferred display list is not used by default.
Disabled Features: skia_deferred_display_list
Version Information
Data exported	2019-01-09T17:51:51.996Z
Chrome version	Chrome/71.0.3578.94
Operating system	Linux 11151.59.0
Software rendering list URL	https://chromium.googlesource.com/chromium/src/+/6da2ba233559398092dabd8dc7bc8e78cd758307/gpu/config/software_rendering_list.json
Driver bug list URL	https://chromium.googlesource.com/chromium/src/+/6da2ba233559398092dabd8dc7bc8e78cd758307/gpu/config/gpu_driver_bug_list.json
ANGLE commit id	f2ed299569c0
2D graphics backend	Skia/71 7469a9341afab19271b8ef07af5c16a0f2c4ccc1-
Command Line	/opt/google/chrome/chrome --ppapi-flash-path=/opt/google/chrome/pepper/libpepflashplayer.so --ppapi-flash-version=32.0.0.101 --ui-prioritize-in-gpu-process --use-gl=egl --enable-native-gpu-memory-buffers --gpu-sandbox-failures-fatal=yes --enable-logging --log-level=1 --use-cras --enable-wayland-server --user-data-dir=/home/chronos --login-profile=user --has-chromeos-keyboard --guest-wallpaper-large=/usr/share/chromeos-assets/wallpaper/guest_large.jpg --guest-wallpaper-small=/usr/share/chromeos-assets/wallpaper/guest_small.jpg --child-wallpaper-large=/usr/share/chromeos-assets/wallpaper/child_large.jpg --child-wallpaper-small=/usr/share/chromeos-assets/wallpaper/child_small.jpg --default-wallpaper-large=/usr/share/chromeos-assets/wallpaper/default_large.jpg --default-wallpaper-small=/usr/share/chromeos-assets/wallpaper/default_small.jpg --enable-consumer-kiosk --enterprise-enrollment-initial-modulus=15 --enterprise-enrollment-modulus-limit=19 --login-manager --first-exec-after-boot --vmodule=nss_cert_database_chromeos=1,*/assistant/*=1,*chromeos/login/*=1,auto_enrollment_controller=1,*/ui/ozone/*=1,*/ui/display/manager/chromeos/*=1,*night_light*=1,update_engine=1,component_updater_service=1,power_button_observer=2,webui_login_view=2,lock_state_controller=2,webui_screen_locker=2,screen_locker=2 --silent-launch
Driver Information
Initialization time	255
In-process GPU	false
Passthrough Command Decoder	false
Sandboxed	true
GPU0	VENDOR = 0x8086 [Intel Open Source Technology Center], DEVICE= 0x0f31 [Mesa DRI Intel(R) Bay Trail ] *ACTIVE*
Optimus	false
AMD switchable	false
Driver vendor	Mesa
Driver version	18.2.0
Driver date	
GPU CUDA compute capability major version	0
Pixel shader version	3.00
Vertex shader version	3.00
Max. MSAA samples	8
Machine model name	
Machine model version	
GL_VENDOR	Intel Open Source Technology Center
GL_RENDERER	Mesa DRI Intel(R) Bay Trail
GL_VERSION	OpenGL ES 3.0 Mesa 18.2.0-devel (git-0f959215c3)
GL_EXTENSIONS	GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_APPLE_texture_max_level GL_EXT_blend_func_extended GL_EXT_blend_minmax GL_EXT_clip_cull_distance GL_EXT_color_buffer_float GL_EXT_compressed_ETC1_RGB8_sub_texture GL_EXT_copy_image GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_draw_buffers_indexed GL_EXT_draw_elements_base_vertex GL_EXT_frag_depth GL_EXT_map_buffer_range GL_EXT_multi_draw_arrays GL_EXT_occlusion_query_boolean GL_EXT_polygon_offset_clamp GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_separate_shader_objects GL_EXT_shader_framebuffer_fetch_non_coherent GL_EXT_shader_integer_mix GL_EXT_texture_border_clamp GL_EXT_texture_compression_dxt1 GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_rg GL_EXT_texture_sRGB_decode GL_EXT_texture_type_2_10_10_10_REV GL_EXT_unpack_subimage GL_INTEL_performance_query GL_KHR_blend_equation_advanced GL_KHR_context_flush_control GL_KHR_debug GL_KHR_no_error GL_KHR_robust_buffer_access_behavior GL_KHR_robustness GL_MESA_shader_integer_functions GL_NV_draw_buffers GL_NV_fbo_color_attachments GL_NV_read_buffer GL_NV_read_depth GL_NV_read_depth_stencil GL_NV_read_stencil GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_EGL_image_external_essl3 GL_OES_EGL_sync GL_OES_compressed_ETC1_RGB8_texture GL_OES_copy_image GL_OES_depth24 GL_OES_depth_texture GL_OES_depth_texture_cube_map GL_OES_draw_buffers_indexed GL_OES_draw_elements_base_vertex GL_OES_element_index_uint GL_OES_fbo_render_mipmap GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_required_internalformat GL_OES_rgb8_rgba8 GL_OES_sample_shading GL_OES_sample_variables GL_OES_shader_multisample_interpolation GL_OES_standard_derivatives GL_OES_stencil8 GL_OES_surfaceless_context GL_OES_texture_3D GL_OES_texture_border_clamp GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object GL_OES_vertex_half_float
Disabled Extensions	GL_KHR_blend_equation_advanced GL_KHR_blend_equation_advanced_coherent
Disabled WebGL Extensions	
Window system binding vendor	Mesa Project
Window system binding version	1.4 (DRI2)
Window system binding extensions	EGL_ANDROID_blob_cache EGL_ANDROID_native_fence_sync EGL_EXT_create_context_robustness EGL_EXT_image_dma_buf_import EGL_EXT_image_dma_buf_import_modifiers EGL_KHR_config_attribs EGL_KHR_create_context EGL_KHR_create_context_no_error EGL_KHR_fence_sync EGL_KHR_get_all_proc_addresses EGL_KHR_gl_colorspace EGL_KHR_gl_renderbuffer_image EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_3D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_image_base EGL_KHR_no_config_context EGL_KHR_reusable_sync EGL_KHR_surfaceless_context EGL_EXT_pixel_format_float EGL_KHR_wait_sync EGL_MESA_configless_context EGL_MESA_drm_image EGL_MESA_image_dma_buf_export
Direct rendering	Yes
Reset notification strategy	0x8252
GPU process crash count	0
Compositor Information
Tile Update Mode	One-copy
Partial Raster	Enabled
GpuMemoryBuffers Status
R_8	CAMERA_AND_CPU_READ_WRITE, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
R_16	Software only
RG_88	SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
BGR_565	GPU_READ
RGBA_4444	Software only
RGBX_8888	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE
RGBA_8888	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE
BGRX_8888	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE
BGRX_1010102	Software only
RGBX_1010102	SCANOUT_CPU_READ_WRITE
BGRA_8888	GPU_READ, SCANOUT, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
RGBA_F16	Software only
YVU_420	GPU_READ
YUV_420_BIPLANAR	SCANOUT_CAMERA_READ_WRITE, SCANOUT_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE, GPU_READ_CPU_READ_WRITE_PERSISTENT
UYVY_422	Software only
Display(s) Information
Info	Display[2785062953156608] bounds=[0,0 1366x768], workarea=[0,0 1366x712], scale=1, internal.
Color space information	{primaries:INVALID, transfer:INVALID, matrix:INVALID, range:INVALID}
Bits per color component	8
Bits per pixel	24
Video Acceleration Information
Decode h264 baseline	up to 4096x4096 pixels
Decode h264 main	up to 4096x4096 pixels
Decode h264 high	up to 4096x4096 pixels
Encode h264 baseline	up to 4096x4096 pixels and/or 30.000 fps
Encode h264 main	up to 4096x4096 pixels and/or 30.000 fps
Encode h264 high	up to 4096x4096 pixels and/or 30.000 fps
Log Messages
[1282:1294:0109/114349.120512:VERBOSE1:drm_device_manager.cc(53)] : Could not initialize DRM device for /sys/devices/platform/vgem/drm/card1
[1282:1294:0109/114351.919497:VERBOSE1:drm_display.cc(104)] : DRM configuring: device=/sys/devices/pci0000:00/0000:00:02.0/drm/card0 crtc=38 connector=60 origin=0,0 size=1366x768

The only work around I have found is to reload Chrome OS to a previous version. Update to version 71.0.3578.94 then attach docking station.  At which point the device appears brand new to Chrome OS.