diff -r 000000000000 -r 6474c204b198 content/canvas/test/webgl-mochitest/webgl-util.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/canvas/test/webgl-mochitest/webgl-util.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,131 @@
+WebGLUtil = (function() {
+  // ---------------------------------------------------------------------------
+  // Error handling (for obvious failures, such as invalid element ids)
+
+  function defaultErrorFunc(str) {
+    console.log('Error: ' + str);
+  }
+
+  var gErrorFunc = defaultErrorFunc;
+  function setErrorFunc(func) {
+    gErrorFunc = func;
+  }
+
+  function error(str) {
+    gErrorFunc(str);
+  }
+
+  // ---------------------------------------------------------------------------
+  // Warning handling (for failures that may be intentional)
+
+  function defaultWarningFunc(str) {
+    console.log('Warning: ' + str);
+  }
+
+  var gWarningFunc = defaultWarningFunc;
+  function setWarningFunc(func) {
+    gWarningFunc = func;
+  }
+
+  function warning(str) {
+    gWarningFunc(str);
+  }
+
+  // ---------------------------------------------------------------------------
+  // WebGL helpers
+
+  function getWebGL(canvasId, requireConformant) {
+    // `requireConformant` will default to falsey if it is not supplied.
+
+    var canvas = document.getElementById(canvasId);
+
+    var gl = null;
+    try {
+      gl = canvas.getContext('webgl');
+    } catch(e) {}
+
+    if (!gl && !requireConformant) {
+      try {
+        gl = canvas.getContext('experimental-webgl');
+      } catch(e) {}
+    }
+
+    if (!gl) {
+      error('WebGL context could not be retrieved from \'' + canvasId + '\'.');
+      return null;
+    }
+
+    return gl;
+  }
+
+  function getContentFromElem(elem) {
+    var str = "";
+    var k = elem.firstChild;
+    while (k) {
+      if (k.nodeType == 3)
+        str += k.textContent;
+
+      k = k.nextSibling;
+    }
+
+    return str;
+  }
+
+  // Returns a valid shader, or null on errors.
+  function createShaderById(gl, id) {
+    var elem = document.getElementById(id);
+    if (!elem) {
+      error('Failed to create shader from non-existent id \'' + id + '\'.');
+      return null;
+    }
+
+    var src = getContentFromElem(elem);
+
+    var shader;
+    if (elem.type == "x-shader/x-fragment") {
+      shader = gl.createShader(gl.FRAGMENT_SHADER);
+    } else if (elem.type == "x-shader/x-vertex") {
+      shader = gl.createShader(gl.VERTEX_SHADER);
+    } else {
+      error('Bad MIME type for shader \'' + id + '\': ' + elem.type + '.');
+      return null;
+    }
+
+    gl.shaderSource(shader, src);
+    gl.compileShader(shader);
+
+    return shader;
+  }
+
+  function createProgramByIds(gl, vsId, fsId) {
+    var vs = createShaderById(gl, vsId);
+    var fs = createShaderById(gl, fsId);
+    if (!vs || !fs)
+      return null;
+
+    var prog = gl.createProgram();
+    gl.attachShader(prog, vs);
+    gl.attachShader(prog, fs);
+    gl.linkProgram(prog);
+
+    if (!gl.getProgramParameter(prog, gl.LINK_STATUS)) {
+      var str = "Shader program linking failed:";
+      str += "\nShader program info log:\n" + gl.getProgramInfoLog(prog);
+      str += "\n\nVert shader log:\n" + gl.getShaderInfoLog(vs);
+      str += "\n\nFrag shader log:\n" + gl.getShaderInfoLog(fs);
+      warning(str);
+      return null;
+    }
+
+    return prog;
+  }
+
+  return {
+    setErrorFunc: setErrorFunc,
+    setWarningFunc: setWarningFunc,
+
+    getWebGL: getWebGL,
+    createShaderById: createShaderById,
+    createProgramByIds: createProgramByIds,
+  };
+})();