Break //ui/gl/ dependency on //ui/ozone.

This CL removes the last code in //ui/gl that depends on //ui/ozone. It
then inverts the dependency so that //ui/ozone depends on //ui/gl and
each OzonePlatform can override GL specific classes.

GLImageOzoneNativePixmap is moved into a new target //ui/ozone/gl. This
is only possible now that the dependency problem has been fixed.

There is an issue with tests for GLImageOzoneNativePixmap. They are
still located in //ui/gl:gl_unittests as they depend on
//ui/gl:test_support. Moving the tests into //ui/ozone:ozone_unittests
has additional dependency problems. A new ozone_gl_unittests target
could be added in the future to avoid this but the remaining tests are
currently disabled anyways.

This is the finally CL in step 2 of the associated bug.

BUG=611142
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2102443003
Cr-Commit-Position: refs/heads/master@{#406765}
24 files changed