Remove unused variables.

These variables trigger compiler warnings (and thus build errors) when
DISALLOW_COPY_AND_ASSIGN is changed to use "= delete", and thus must be removed
before that lands.

https://codereview.chromium.org/1701063003 (a while ago) added the variable in
chrome/browser/chromeos/arc/arc_service_launcher.h, which was never used.

https://codereview.chromium.org/1866043006 removed the uses of the variables in
cc/tiles/tile_manager.cc, but not the variables themselves.

https://codereview.chromium.org/1899363002 added all the media/ plumbing in
order to set MojoVideoDecoder::gpu_factories_, which is unused.

https://codereview.chromium.org/1961573002 added the variable in
net/spdy/spdy_framer_test.cc, which is unused.

BUG=447156
TEST=none
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review-Url: https://codereview.chromium.org/2018453002
Cr-Commit-Position: refs/heads/master@{#396289}
5 files changed