Change GetIntegerv(IMPLEMENTATION_COLOR_READ_FORMAT/TYPE) behavior.

Change GetIntegerv(IMPLEMENTATION_COLOR_READ_FORMAT/TYPE) behavior.

1) Clean up a bit mess with framebuffer target
2) On desktop GL, no longer query the driver for these two enums. The drivers
   won't provide the answers anyway.  Instead, use internal logic to determine
   the format/type

BUG=662802
TEST=gpu_unittests,webgl_conformance
R=vmiura@chromium.org,ericrk@chromium.org
NOTRY=true
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/2577293002
Cr-Commit-Position: refs/heads/master@{#439206}
(cherry picked from commit a11bcfb22a66f56d8a885efd89e7979d60d638b4)

Committed: https://chromium.googlesource.com/chromium/src/+/ca5a6fb3e2be3f4da8329090e906c0d5fa1b7820

[Zhenyao Mo, 2016-12-22 00:27:56]

Description was changed from

==========
Change GetIntegerv(IMPLEMENTATION_COLOR_READ_FORMAT/TYPE) behavior.

1) Clean up a bit mess with framebuffer target
2) On desktop GL, no longer query the driver for these two enums. The drivers
   won't provide the answers anyway.  Instead, use internal logic to determine
   the format/type

BUG=662802
TEST=gpu_unittests,webgl_conformance
R=vmiura@chromium.org,ericrk@chromium.org
NOTRY=true
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/2577293002
Cr-Commit-Position: refs/heads/master@{#439206}
(cherry picked from commit a11bcfb22a66f56d8a885efd89e7979d60d638b4)
==========

to

==========
Change GetIntegerv(IMPLEMENTATION_COLOR_READ_FORMAT/TYPE) behavior.

1) Clean up a bit mess with framebuffer target
2) On desktop GL, no longer query the driver for these two enums. The drivers
   won't provide the answers anyway.  Instead, use internal logic to determine
   the format/type

BUG=662802
TEST=gpu_unittests,webgl_conformance
R=vmiura@chromium.org,ericrk@chromium.org
NOTRY=true
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/2577293002
Cr-Commit-Position: refs/heads/master@{#439206}
(cherry picked from commit a11bcfb22a66f56d8a885efd89e7979d60d638b4)

Committed:
https://chromium.googlesource.com/chromium/src/+/ca5a6fb3e2be3f4da8329090e906...
==========

[Zhenyao Mo, 2016-12-22 00:27:58]

Committed patchset #1 (id:1) manually as
ca5a6fb3e2be3f4da8329090e906c0d5fa1b7820.