UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36

Example URL:

Steps to reproduce the problem:
1. Own a iGPU and dGPU system.
2. Use bumblebee (or other ways) to disable the power hungry dGPU.
3. Look at chrome://gpu and see that chromium fails to "GPU process was unable to boot: GPU process launch failed."

What is the expected behavior?
Selection of the iGPU.

glxinfo extract:
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Intel Open Source Technology Center (0x8086)
    Device: Mesa DRI Intel(R) Haswell Mobile  (0x416)
    Version: 17.2.6
    Accelerated: yes
    Video memory: 1536MB
    Unified memory: yes
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.1
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile
OpenGL core profile version string: 4.5 (Core Profile) Mesa 17.2.6
OpenGL core profile shading language version string: 4.50
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

What went wrong?
Selection of the dGPU.

Did this work before? Yes Not sure - I would guess 58 or earlier.

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

Does this work in other browsers? Yes

Chrome version: 63.0.3239.84  Channel: n/a
OS Version: Arch - latest
Flash Version: -

Contents of chrome://gpu: 
Note: To properly save this page, select the "Webpage, Complete" option in the Save File dialog.
Graphics Feature Status
Canvas: Software only. Hardware acceleration disabled
CheckerImaging: Disabled
Flash: Software only, hardware acceleration unavailable
Flash Stage3D: Software only, hardware acceleration unavailable
Flash Stage3D Baseline profile: Software only, hardware acceleration unavailable
Compositing: Software only, hardware acceleration unavailable
Multiple Raster Threads: Unavailable
Native GpuMemoryBuffers: Software only, hardware acceleration unavailable
Rasterization: Software only, hardware acceleration unavailable
Video Decode: Software only, hardware acceleration unavailable
Video Encode: Software only, hardware acceleration unavailable
WebGL: Unavailable
WebGL2: Unavailable
Problems Detected
GPU process was unable to boot: GPU process launch failed.
Disabled Features: all
Accelerated 2D canvas is unavailable: either disabled via blacklist or the command line.
Disabled Features: 2d_canvas
Checker-imaging has been disabled via finch trial or the command line.
Disabled Features: checker_imaging
Version Information
Data exported	07/12/2017, 20:38:20
Chrome version	Chrome/63.0.3239.84
Operating system	Linux 4.14.4-1-ck-haswell
Software rendering list version	0
Driver bug list version	10.34
ANGLE commit id	unknown hash
2D graphics backend	Skia/63 dbae7001c9805fb0a4b18fd0cbc889941cb39db4-
Command Line	/usr/lib/chromium/chromium --enable-native-gpu-memory-buffers --force-device-scale-factor=1.6 --flag-switches-begin --disable-accelerated-2d-canvas --enable-fast-unload --enable-gpu-rasterization --enable-zero-copy --gpu-rasterization-msaa-sample-count=0 --ignore-gpu-blacklist --enable-features=ExpensiveBackgroundTimerThrottling,OffMainThreadFetch --flag-switches-end
Driver Information
Initialization time	0
In-process GPU	true
Passthrough Command Decoder	false
Supports overlays	false
Sandboxed	false
GPU0	VENDOR = 0x10de, DEVICE= 0x0fe4 *ACTIVE*
GPU1	VENDOR = 0x8086, DEVICE= 0x0416
Optimus	true
Optimus	true
AMD switchable	false
Driver vendor	NVIDIA
Driver version	387.22
Driver date	
Pixel shader version	
Vertex shader version	
Max. MSAA samples	
Machine model name	
Machine model version	
GL_VENDOR	NVIDIA Corporation
GL_RENDERER	GeForce GT 750M/PCIe/SSE2
GL_VERSION	4.6.0 NVIDIA 387.22
GL_EXTENSIONS	
Disabled Extensions	
Window system binding vendor	
Window system binding version	
Window system binding extensions	
Window manager	i3
XDG_CURRENT_DESKTOP	i3
Compositing manager	No
Direct rendering	Yes
Reset notification strategy	0x0000
GPU process crash count	1
System visual ID	0
RGBA visual ID	0
Compositor Information
Tile Update Mode	Zero-copy
Partial Raster	Enabled
GpuMemoryBuffers Status
ATC	Software only
ATCIA	Software only
DXT1	Software only
DXT5	Software only
ETC1	Software only
R_8	Software only
R_16	Software only
RG_88	Software only
BGR_565	Software only
RGBA_4444	Software only
RGBX_8888	Software only
RGBA_8888	Software only
BGRX_8888	Software only
BGRA_8888	Software only
RGBA_F16	Software only
YVU_420	Software only
YUV_420_BIPLANAR	Software only
UYVY_422	Software only
Display(s) Information
Info	Display[21691165392764928] bounds=0,1125 2000x1125, workarea=0,1125 2000x1125, scale=1.6, external
Color space information	{primaries:INVALID, transfer:INVALID, matrix:INVALID, range:INVALID, icc_profile_id:0}
Bits per color component	8
Bits per pixel	24
Info	Display[4693785849697538] bounds=0,0 2000x1125, workarea=0,0 2000x1125, scale=1.6, external
Color space information	{primaries:INVALID, transfer:INVALID, matrix:INVALID, range:INVALID, icc_profile_id:0}
Bits per color component	8
Bits per pixel	24
Log Messages
GpuProcessHostUIShim: The GPU process exited with code 1024.

This is quite similar to [1] which is "WontFix" because 'it is not a chromium bug'. That reporter also opened an issue against ANGLE [2] and that too is "WontFix" as 'ANGLE is not yet used for Linux' and want that bug being opened against chromium. If this is _really_ not a chromium bug, please do tell me where to open the issue "correctly".

Thank you!

[1] https://bugs.chromium.org/p/chromium/issues/detail?id=749922
[2] https://bugs.chromium.org/p/angleproject/issues/detail?id=2120