Merge 117918 - Must set/reset pixel unpack alignment to 1 during texSubImage2D

LayoutTests/fast/canvas/webgl/resources/tex-image-and-sub-image-2d-with-image.js

 function generateTest(pixelFormat, pixelType, pathToTestRoot, prologue) {
     var wtu = WebGLTestUtils;
     var gl = null;
     var textureLoc = null;
     var successfullyParsed = false;
     var imgCanvas;
     var red = [255, 0, 0];
     var green = [0, 255, 0];
 
     var init = function()
@@ skipping 108 matching lines @@
 
     function runTest3(image) {
         runTestOnImage(image);
 
         glErrorShouldBe(gl, gl.NO_ERROR, "should be no errors");
         finishTest();
     }
 
     return init;
 }