Verify texImage2D and texSubImage2D code paths taking canvas elements (RGBA/HALF_FLOAT_OES)

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

PASS Successfully enabled OES_texture_half_float extension
Testing texImage2D with flipY=true
Checking lower left corner
PASS shouldBe 0,255,0
Checking upper left corner
PASS shouldBe 255,0,0
Testing texImage2D with flipY=false
Checking lower left corner
PASS shouldBe 255,0,0
Checking upper left corner
PASS shouldBe 0,255,0
Testing texSubImage2D with flipY=true
Checking lower left corner
PASS shouldBe 0,255,0
Checking upper left corner
PASS shouldBe 255,0,0
Testing texSubImage2D with flipY=false
Checking lower left corner
PASS shouldBe 255,0,0
Checking upper left corner
PASS shouldBe 0,255,0
PASS getError was expected value: NO_ERROR : should be no errors
PASS successfullyParsed is true

TEST COMPLETE