chromium: don't pass is_official_build=true when doing a component-build

[Villemoes]

When setting the PACKAGECONFIG component-build, the build breaks
immediately due to this from the toplevel BUILD.gn:

if (is_official_build) {
  # An official (maximally optimized!) component (optimized for build times)
  # build doesn't make sense and usually doesn't work.
  assert(!is_component_build)
}

So we must make is_official_build the negative of component-build.

[Villemoes]

Ping. Is there any other way to get the component-build packageconfig working? It is officially listed in the README.md, but does it actually currently work for anybody?

[rakuco]

The patch looks valid to me, but it does seem to indicate that nobody has tested the component build knob in ages. Do you get a working binary if you build the recipe with this patch?

[Villemoes]

Unfortunately, no, I don't even get a binary. The build fails towards the end with an error I can't decipher:

./v8_context_snapshot_generator: symbol lookup error: ...out/Release/libbase_i18n.so: undefined symbol: UCNV_FROM_U_CALLBACK_SKIP_71
./v8-qemu-wrapper.sh failed with exit code 127

But that symbol does exist in libicuuc.so, and libbase_i18n.so itself has been succesfully created (and libicuuc.so is in the solibs= for libbase_i18n.so, and also listed as NEEDED when I run readelf -d on it). So I suppose this is some defect in the v8_context_snapshot_generator tool, but I have no idea how to proceed or fix it.