chromium: Add v4l2 m2m stateless decode configuration options

Add configuration options to enable hardware video decoding using
stateless V4L2 M2M device. This allows offloading e.g. h264 video
playback to Hantro VPU on i.MX8MP where this was tested. To make
that work, enable 'use-v4l2' and 'proprietary-codecs' PACKAGECONFIG.

For i.MX8MP the following additional udev rules are mandatory:
```
SUBSYSTEM=="video4linux", ATTR{name}=="nxp,imx8mm-vpu-g1-dec", SYMLINK+="video-dec%n"
SUBSYSTEM=="video4linux", ATTR{name}=="nxp,imx8mm-vpu-g2-dec", SYMLINK+="video-dec%n"
SUBSYSTEM=="media", ATTR{model}=="hantro-vpu", SYMLINK+="media-dec%n"
```

This commit was implemented with much great help from Jianfeng Liu .

Signed-off-by: Marek Vasut <[email protected]>

Author: Marek Vasut

meta-chromium/recipes-browser/chromium/chromium-gn.inc

@@ -109,7 +109,7 @@ BUILD_CC:toolchain-clang = "clang"
 BUILD_CXX:toolchain-clang = "clang++"
 BUILD_LD:toolchain-clang = "clang"
 
-PACKAGECONFIG ??= "upower use-egl"
+PACKAGECONFIG ??= "upower use-egl use-v4l2"
 
 # this makes sure the dependencies for the EGL mode are present; otherwise, the configure scripts
 # automatically and silently fall back to GLX
@@ -143,6 +143,10 @@ PACKAGECONFIG[upower] = ",,,upower"
 # but remember to also use proprietary codecs so that H.264 is supported. Also note
 # that not all the hardware configs might be supported.
 PACKAGECONFIG[use-vaapi] = "use_vaapi=true use_libgav1_parser=true,use_vaapi=false,libva"
+# Enable stateless V4L2 M2M video decoding support.
+# This requires 'proprietary-codecs' PACKAGECONFIG
+# to decode h264 streams on the V4L2 M2M device.
+PACKAGECONFIG[use-v4l2] = "use_v4l2_codec=true,use_v4l2_codec=false"
 
 # Base GN arguments, mostly related to features we want to enable or disable.
 GN_ARGS = " \
@@ -360,6 +364,7 @@ CHROMIUM_EXTRA_ARGS ?= " \
         ${@bb.utils.contains('PACKAGECONFIG', 'use-egl', '--use-angle=gles-egl', '', d)} \
         ${@bb.utils.contains('PACKAGECONFIG', 'kiosk-mode', '--kiosk --no-first-run --incognito', '', d)} \
         ${@bb.utils.contains('PACKAGECONFIG', 'gtk4', '--gtk-version=4', '', d)} \
+        ${@bb.utils.contains('PACKAGECONFIG', 'use-v4l2', '--ozone-platform-hint=wayland --enable-features=AcceleratedVideoDecoder,AcceleratedVideoDecodeLinuxGL,AcceleratedVideoDecodeLinuxZeroCopyGL', '', d)} \
 "
 
 # V8's JIT infrastructure requires binaries such as mksnapshot and