The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9

commit 5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9
Author: Makoto Shimazu <shimazu@chromium.org>
Date: Tue Nov 28 05:47:30 2017

Use mojo struct for EmbeddedWorkerStartParams

This patch removes [Native] and IPC_STRUCT for EmbeddedWorkerStartParams. In a
following patch, we can move all of params passed to
EmbeddedWorkerInstanceClient::StartWorker() to the
mojom::EmbeddedWorkerStartParams.
This patch is adding a typemap from content.mojom.EmbeddedWorkerStartParams to
content::EmbeddedWorkerStartParams in order to avoid fixing all users of the
params.

Bug:  776263 
Change-Id: I7973e49be869b67e86e1a1b6cee7891b17c2f997
Reviewed-on: https://chromium-review.googlesource.com/784732
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519584}
[modify] https://crrev.com/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9/content/browser/service_worker/service_worker_version_unittest.cc
[modify] https://crrev.com/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9/content/common/native_types.mojom
[modify] https://crrev.com/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9/content/common/service_worker/embedded_worker.mojom
[modify] https://crrev.com/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9/content/common/service_worker/embedded_worker.typemap
[modify] https://crrev.com/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9/content/common/service_worker/embedded_worker_messages.h
[add] https://crrev.com/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9/content/common/service_worker/embedded_worker_start_params_struct_traits.cc
[add] https://crrev.com/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9/content/common/service_worker/embedded_worker_start_params_struct_traits.h
[modify] https://crrev.com/5dc5ece2a33c9082bc233ee4ebc10f1bbc5170d9/content/common/web_preferences.typemap

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/82ec604ded0636980c3ea71d89d61e5a885da56c

commit 82ec604ded0636980c3ea71d89d61e5a885da56c
Author: Makoto Shimazu <shimazu@chromium.org>
Date: Thu Dec 21 01:39:32 2017

Use mojo struct for EmbeddedWorkerStartParams without typemap

This patch removes typemap and struct traits for EmbeddedWorkerStartParams.
After this patch, we can move all of interfaces passed on StartWorker() as
arguments into that struct.

Bug:  776263 
Change-Id: Ic207e428ccda98c9f1152dfd4c43a5f5a7d78460
Reviewed-on: https://chromium-review.googlesource.com/835928
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#525556}
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/embedded_worker_instance.cc
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/embedded_worker_instance.h
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/embedded_worker_instance_unittest.cc
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/embedded_worker_test_helper.cc
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/embedded_worker_test_helper.h
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/service_worker_context_unittest.cc
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/service_worker_job_unittest.cc
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/service_worker_process_manager_unittest.cc
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/browser/service_worker/service_worker_version.cc
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/common/BUILD.gn
[delete] https://crrev.com/dea3d7abb6ccc703942ae522dd2069d70dbd4b68/content/common/service_worker/embedded_worker.typemap
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/common/service_worker/embedded_worker_messages.h
[delete] https://crrev.com/dea3d7abb6ccc703942ae522dd2069d70dbd4b68/content/common/service_worker/embedded_worker_settings.h
[delete] https://crrev.com/dea3d7abb6ccc703942ae522dd2069d70dbd4b68/content/common/service_worker/embedded_worker_start_params.cc
[delete] https://crrev.com/dea3d7abb6ccc703942ae522dd2069d70dbd4b68/content/common/service_worker/embedded_worker_start_params.h
[delete] https://crrev.com/dea3d7abb6ccc703942ae522dd2069d70dbd4b68/content/common/service_worker/embedded_worker_start_params_struct_traits.cc
[delete] https://crrev.com/dea3d7abb6ccc703942ae522dd2069d70dbd4b68/content/common/service_worker/embedded_worker_start_params_struct_traits.h
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/common/typemaps.gni
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/renderer/service_worker/embedded_worker_instance_client_impl.cc
[modify] https://crrev.com/82ec604ded0636980c3ea71d89d61e5a885da56c/content/renderer/service_worker/embedded_worker_instance_client_impl.h

This issue has been fixed by https://chromium-review.googlesource.com/835934. 
I've attached a wrong bug number to the CL...