Can you provide more information here? Do you know which dependencies are missing? What error message are you getting?

You can find it in the following review:
https://chromium-review.googlesource.com/c/chromium/src/+/873642

OK, that at least answers the "which dependencies are missing" part. In the future, please add more information to your bug reports even if you're already working on them, otherwise other people interested in the same area don't know what's going on and can't help with reviews (for example, it's still unclear to me what problem you're having since Chromium's build isn't broken in any of the bots).

Ok, next time I'll do more detailed descriptions, sorry for the inconvenience.

bindings_modules_impl always fails to compile when it is build directly from a clean build directory. When buildbots are building other big targets like chrome or some tests then required mojo files will be generated earlier by the other targets dependencies. However it may randomly fail (rare case) when bindings_modules_impl compilation is built early.

At the beginning I had following error on our buildbot:
FAILED: obj/third_party/WebKit/Source/bindings/modules/v8/bindings_modules_impl/bindings_modules_impl_jumbo_2.obj 
../../third_party/WebKit/Source\modules/gamepad/GamepadHapticActuator.h(11,10):  fatal error: 'device/gamepad/public/interfaces/gamepad.mojom-blink.h' file not found

When I started fixing this issue in bindings_modules_impl other missing dependencies occurred (see review).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6dcaabf221e9d6a0061ff609b5c24f0a370d5f1b

commit 6dcaabf221e9d6a0061ff609b5c24f0a370d5f1b
Author: Michał Pichliński <mpichlinski@opera.com>
Date: Wed Feb 07 09:47:34 2018

Fixed missing mojo interfaces dependencies for bindings_modules_impl.

Bug:  803441 
Change-Id: Ie076c368a0dbfb8178362bb8a79e29f0feff9197
Reviewed-on: https://chromium-review.googlesource.com/873642
Commit-Queue: Colin Blundell <blundell@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534968}
[modify] https://crrev.com/6dcaabf221e9d6a0061ff609b5c24f0a370d5f1b/services/device/public/interfaces/BUILD.gn
[modify] https://crrev.com/6dcaabf221e9d6a0061ff609b5c24f0a370d5f1b/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn