Add support for jumbo compilations to the rest of //ui

Jumbo is the Chromium implementation of a Unity build system aimed at
dramatically lowering the compilation times, especially for those
without access to goma.

In reference testing, this patch reduces the effort to compile
content_shell+chrome+blink_tests by about 9 CPU minutes, 1-2% of the
total effort. Earlier patches saved more so the total build effort
reduction in //ui is about 41 CPU minutes.

There is still some code in ui that doesn't use jumbo. Specifically
most of the tests.

Bug: 773275
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: Ie59fec4b67fc1e3d6855d04a4b9a1088e0a08768
Reviewed-on: https://chromium-review.googlesource.com/834348
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#589473}
10 files changed