Support cube map dest target for CopyTextureCHROMIUM extension
DIRECT_DRAW path isn't available for cube map dest texture if it isn't
cube map complete. So, use DRAW_AND_COPY path in this scenario, i.e.
draw to a 2D intemediate texture first, then copy from the 2d texture to
the cube map dest texture.
Also, this CL makes DIRECT_COPY and DRAW_AND_COPY path work well for cube
map dest texture.
BUG=612542
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/2656563002
Cr-Commit-Position: refs/heads/master@{#446940}
6 files changed
