GitLab

Unify texture and fbo creation for ES2 and ES3 in gl_tests

These are some reasons to do this:
1. Code can be shared between ES2 and ES3 tests.
2. We don't always create GL_TEXTURE_2D textures in test.
3. We may create textures many times in a single test. In such case,
  it's ugly to delete the textures created in Setup at the beginning of
  each test round.

BUG=612542
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/2602933002
Cr-Commit-Position: refs/heads/master@{#441297}