This is a V8 bug, not a Blink one. The way the code's written it looks like this is only expected to work with a standalone V8 build, but you should file a bug at https://bugs.chromium.org/p/v8 to be sure.

The issue seems to be out of TE-scope as it is related to Build and V8. Hence, adding label TE-NeedsTriageHelp for further help in triaging this issue.

Thanks...!!

It's supported in v8 standalone. I don't know if there's support in Chrome. I'd defer to Intel for a good answer.

Debugging a bit:
https://cs.chromium.org/chromium/src/v8/BUILD.gn?q=vtune:v8_vtune&sq=package:chromium&l=3082
can't really work in Chrome, since the // refers to the project base, which is different when embedded. Does it work for you if you just remove the //? Then it is a relative dependency. Feel free to make a CL with that change.

Thank you. I've opened a v8 bug as suggested. 
If I just remove '//' it doesn't work, and has more dependency issues like:

ERROR Unresolved dependencies.
//v8/src/third_party/vtune:v8_vtune(//build/toolchain/win:win_clang_x64)
  needs //:v8(//build/toolchain/win:win_clang_x64)

Needed to look at JITed code profile, f12 profiler tool seems the way to go then?

I think the dependencies within vtune might be wrong, too. They should all be relative and not use the // anywhere. In standalone mode, v8 is in // but in chromium, v8 is in //v8/. So all dependency paths must be relative.

I sent https://chromium-review.googlesource.com/c/v8/v8/+/980557 yesterday, it should take care of that.

CL, lg. If there's another v8-side bug, could you please link it to this one?

The following revision refers to this bug:
  https://chromium.googlesource.com/v8/v8.git/+/41aad4bcc05f900ef5407378698a6385507fa8bf

commit 41aad4bcc05f900ef5407378698a6385507fa8bf
Author: Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
Date: Wed Mar 28 09:36:35 2018

[build] Do not use absolute paths in v8_enable_vtunejit-related blocks.

This prevents the flag from being set from e.g. Chromium. Instead, just use
relative paths like everything else in the build system.

Bug: chromium:825347,  v8:7601 

Change-Id: I080d9999b0b63bafc2c1978f70322eb48814a3b8
Reviewed-on: https://chromium-review.googlesource.com/980557
Commit-Queue: Raphael Kubo da Costa <raphael.kubo.da.costa@intel.com>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52263}
[modify] https://crrev.com/41aad4bcc05f900ef5407378698a6385507fa8bf/BUILD.gn
[modify] https://crrev.com/41aad4bcc05f900ef5407378698a6385507fa8bf/src/third_party/vtune/BUILD.gn

> If there's another v8-side bug, could you please link it to this one?

I've marked  bug v8:7601  as blocking this one (it's the same report but filed against V8).

The commit (once there's a V8 roll) above should allow one to set v8_enable_vtunejit=true from Chromium. I don't know if it makes any difference or if something needs to be done on the Blink/Chromium side for things to work smoothly though.

Raphael, since you authored the CL, I am assigning this to you so it goes out of our V8 infra triage queue. Please re-assign if this is incorrect.