[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

(The original reviewed CL is https://codereview.chromium.org/1927593005/)

This CL change the default format/type from RGBA/UNSIGNED_BYTE to RGBA/FLOAT.

Also, simplify querying IMPLMENTATION_READ_COLOR_FORMAT/TYPE by
always calling down to the driver (even if the two enums are not
supported) and fall back to internal decision if a GL error is
generated.

BUG=607283, 607936
TEST=webgl_conformance,webgl2_conformance
R=piman@chromium.org,kbr@chromium.org,bajones@chromium.org
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
NOTRY=true
TBR=kbr@chromium.org,piman@chromium.org

Committed: https://crrev.com/9192d283d15db880e62fcccdd02adda1c3ad0188
Cr-Commit-Position: refs/heads/master@{#390702}

[Zhenyao Mo, 2016-04-29 18:16:49]

https://codereview.chromium.org/1938493002/diff/1/gpu/command_buffer/tests/gl...
File gpu/command_buffer/tests/gl_readback_unittest.cc (right):

https://codereview.chromium.org/1938493002/diff/1/gpu/command_buffer/tests/gl...
gpu/command_buffer/tests/gl_readback_unittest.cc:147: // type is HALF_FLOAT_OES.
Likely it's due to a driver bug. crbug.com/607936.
This is the added part from the original CL: in this CL, we also disable the
test on ANDROID.

[Zhenyao Mo, 2016-04-29 18:17:24]

Description was changed from

==========
[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

(The original reviewed CL is https://codereview.chromium.org/1927593005/)

This CL change the default format/type from RGBA/UNSIGNED_BYTE to RGBA/FLOAT.

Also, simplify querying IMPLMENTATION_READ_COLOR_FORMAT/TYPE by
always calling down to the driver (even if the two enums are not
supported) and fall back to internal decision if a GL error is
generated.

BUG=607283,607936
TEST=webgl_conformance,webgl2_conformance
R=piman@chromium.org,kbr@chromium.org,bajones@chromium.org
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
NOTRY=true
==========

to

==========
[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

(The original reviewed CL is https://codereview.chromium.org/1927593005/)

This CL change the default format/type from RGBA/UNSIGNED_BYTE to RGBA/FLOAT.

Also, simplify querying IMPLMENTATION_READ_COLOR_FORMAT/TYPE by
always calling down to the driver (even if the two enums are not
supported) and fall back to internal decision if a GL error is
generated.

BUG=607283,607936
TEST=webgl_conformance,webgl2_conformance
R=piman@chromium.org,kbr@chromium.org,bajones@chromium.org
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
NOTRY=true
TBR=kbr@chromium.org,piman@chromium.org
==========

[Zhenyao Mo, 2016-04-29 18:17:28]

The CQ bit was checked by zmo@chromium.org

[commit-bot: I haz the power, 2016-04-29 18:17:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1938493002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1938493002/1

[commit-bot: I haz the power, 2016-04-29 18:23:08]

Description was changed from

==========
[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

(The original reviewed CL is https://codereview.chromium.org/1927593005/)

This CL change the default format/type from RGBA/UNSIGNED_BYTE to RGBA/FLOAT.

Also, simplify querying IMPLMENTATION_READ_COLOR_FORMAT/TYPE by
always calling down to the driver (even if the two enums are not
supported) and fall back to internal decision if a GL error is
generated.

BUG=607283,607936
TEST=webgl_conformance,webgl2_conformance
R=piman@chromium.org,kbr@chromium.org,bajones@chromium.org
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
NOTRY=true
TBR=kbr@chromium.org,piman@chromium.org
==========

to

==========
[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

(The original reviewed CL is https://codereview.chromium.org/1927593005/)

This CL change the default format/type from RGBA/UNSIGNED_BYTE to RGBA/FLOAT.

Also, simplify querying IMPLMENTATION_READ_COLOR_FORMAT/TYPE by
always calling down to the driver (even if the two enums are not
supported) and fall back to internal decision if a GL error is
generated.

BUG=607283,607936
TEST=webgl_conformance,webgl2_conformance
R=piman@chromium.org,kbr@chromium.org,bajones@chromium.org
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
NOTRY=true
TBR=kbr@chromium.org,piman@chromium.org
==========

[commit-bot: I haz the power, 2016-04-29 18:23:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-30 17:27:28]

Patchset 1 (id:??) landed as
https://crrev.com/9192d283d15db880e62fcccdd02adda1c3ad0188
Cr-Commit-Position: refs/heads/master@{#390702}

[commit-bot: I haz the power, 2016-04-30 18:01:31]

Description was changed from

==========
[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

(The original reviewed CL is https://codereview.chromium.org/1927593005/)

This CL change the default format/type from RGBA/UNSIGNED_BYTE to RGBA/FLOAT.

Also, simplify querying IMPLMENTATION_READ_COLOR_FORMAT/TYPE by
always calling down to the driver (even if the two enums are not
supported) and fall back to internal decision if a GL error is
generated.

BUG=607283,607936
TEST=webgl_conformance,webgl2_conformance
R=piman@chromium.org,kbr@chromium.org,bajones@chromium.org
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
NOTRY=true
TBR=kbr@chromium.org,piman@chromium.org
==========

to

==========
[Reland] Fix ReadPixels from float fbo buffer in ES2/WebGL1.

(The original reviewed CL is https://codereview.chromium.org/1927593005/)

This CL change the default format/type from RGBA/UNSIGNED_BYTE to RGBA/FLOAT.

Also, simplify querying IMPLMENTATION_READ_COLOR_FORMAT/TYPE by
always calling down to the driver (even if the two enums are not
supported) and fall back to internal decision if a GL error is
generated.

BUG=607283,607936
TEST=webgl_conformance,webgl2_conformance
R=piman@chromium.org,kbr@chromium.org,bajones@chromium.org
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
NOTRY=true
TBR=kbr@chromium.org,piman@chromium.org

Committed: https://crrev.com/9192d283d15db880e62fcccdd02adda1c3ad0188
Cr-Commit-Position: refs/heads/master@{#390702}
==========