Improve indexed gl state related GL commands.

1) draw* calls check for transformfeedback states.
2) add auto-generated parameter validation for unsafe commands
   (and remove them from handwritten code)
3) Implement indexed UNIFORM_BUFFER bindings tracking and
   restoring in context switching
4) shadow GetIntegeri_v and GetInteger64i_v
5) Improve validation for FramebufferTextureLayer().

BUG=604436
TEST=gpu_unittests, webgl2_conformance
[email protected],[email protected]
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/1949303003
Cr-Commit-Position: refs/heads/master@{#392140}
17 files changed