The code that live in ui/gl/* had some code in the old gfx:: namespace
and other code in the new gl:: namespace. This isn't ideal. Do a mass
rename of all namespaces ui/gl/* and update all references chromium
wide. Mostly automated CL based on the follow steps.

1. Update ui/gl/generate_bindings.py generate code in namespace gl
   instead of namespace gfx and autogen bindings.
2. Update the namespaces in ui/gl/* from namespace gfx to namespace gl.
3. Semi-manually fix the namespace on forward declarations of classes
   that moved namespace.
4. Use a widescale grep/perl replacement on all symbols that moved
   namespaces.
5. Use grep/perl replacement on symbols that are actually in namespace
   gfx but used in namespace gl to add fully qualified name.
6. git cl format.

TBR=watk@chromium.org,sdefresne@chromium.org,tsepez@chromium.org
BUG=none
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review-Url: https://codereview.chromium.org/1998723002
Cr-Commit-Position: refs/heads/master@{#396173}