[mojo] include mojo header in /content/renderer/dom_storage

This is preparation CL to use forward declaration only header in mojo's
generated code.
If we include forward declaration only header in mojo's generated code, we need
to include mojo header files in some places where definition is necessary.

master CL is in
https://chromium-review.googlesource.com/c/chromium/src/+/1438975

This CL was uploaded by git cl split.

R=pwnall@chromium.org

CC: rockot@google.com
Bug: 922875
Change-Id: Id677ae7ecf8591b61dfec8dec5cc2f695b17a1ba
Reviewed-on: https://chromium-review.googlesource.com/c/1447052
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#627655}
2 files changed