[jumbo] Rename one of the HasAlpha functions in DXGI code

In jumbo builds many files are compiled together in the same
translation unit, and there share the same anonymous namespace.
By copying functions from gl_image_dxgi.cc into
gl_image_gxgi_swap_chain.cc without changing the function names
jumbo builds got collisions between two HasAlpha and two
SupportedBindFormat. Since they are also slightly modified,
reusing the function is not a direction option so this renames
the new set of functions by adding a SwapChain prefix.

TBR=piman@chromium.org,ashithasantosh@google.com

Bug: 939655
Change-Id: I3190aa8cbb3c87b0be8be821298a67906be0abd2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1594581
Reviewed-by: Daniel Bratell <bratell@opera.com>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#656372}
1 file changed