The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8edf606b24fe8f69becdbf0afe8ae69c16375482

commit 8edf606b24fe8f69becdbf0afe8ae69c16375482
Author: zmo <zmo@chromium.org>
Date: Tue Apr 12 04:33:14 2016

Enable TexStorage on Desktop GL lower than 4.2

On MacOSX core profile, the highest GL supported is 4.1. However, TexStorage functions are only included in 4.2 or higher.

However, it seems that most (if not all) mac drivers expose ARB_texture_storage extension, so we simply expose the GL binding when the extension exists.

This CL also consolidate similar code in handling TexStorage2D and 3D.

BUG= 601513 
TEST=gpu_unittests
R=piman@chromium.org,kbr@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

Review URL: https://codereview.chromium.org/1872663002

Cr-Commit-Position: refs/heads/master@{#386586}

[modify] https://crrev.com/8edf606b24fe8f69becdbf0afe8ae69c16375482/content/test/gpu/gpu_tests/webgl2_conformance_expectations.py
[modify] https://crrev.com/8edf606b24fe8f69becdbf0afe8ae69c16375482/gpu/command_buffer/service/feature_info.cc
[modify] https://crrev.com/8edf606b24fe8f69becdbf0afe8ae69c16375482/gpu/command_buffer/service/gles2_cmd_decoder.cc
[modify] https://crrev.com/8edf606b24fe8f69becdbf0afe8ae69c16375482/gpu/command_buffer/service/gles2_cmd_decoder_unittest.cc
[modify] https://crrev.com/8edf606b24fe8f69becdbf0afe8ae69c16375482/gpu/command_buffer/service/gles2_cmd_decoder_unittest_textures.cc
[modify] https://crrev.com/8edf606b24fe8f69becdbf0afe8ae69c16375482/ui/gl/generate_bindings.py
[modify] https://crrev.com/8edf606b24fe8f69becdbf0afe8ae69c16375482/ui/gl/gl_bindings_autogen_gl.cc