diff --git a/content/canvas/test/webgl/conformance/reading/read-pixels-test.html b/content/canvas/test/webgl/conformance/reading/read-pixels-test.html
index 6081a7474352..0c86193f2c46 100644
--- a/content/canvas/test/webgl/conformance/reading/read-pixels-test.html
+++ b/content/canvas/test/webgl/conformance/reading/read-pixels-test.html
@@ -19,6 +19,7 @@ found in the LICENSE file.
 <div id="console"></div>
 <script>
 description("Checks that ReadPixels works as expected.");
+testPassed("read-pixels-test start: " + (new Date().getTime()));
 
 var wtu = WebGLTestUtils;
 var canvas = document.getElementById("example");
@@ -180,6 +181,7 @@ function continueTestPart1() {
 }
 
 function continueTestPart2() {
+testPassed("read-pixels-test continueTestPart2: " + (new Date().getTime()));
   gl.viewport(0, 0, 1024, 1024);
   var program = wtu.setupTexturedQuad(gl);
   var loc = gl.getUniformLocation(program, "tex");
@@ -221,7 +223,9 @@ function continueTestPart2() {
   // bug 763355: temporary logging of exceptions here to understand intermittent timeout
   // in this test, apparently in this finishTest() call.
   try {
+    testPassed("read-pixels-test calling finishTest: " + (new Date().getTime()));
     finishTest();
+    testPassed("read-pixels-test after finishTest: " + (new Date().getTime()));
   } catch(e) {
     testFailed("finishTest generated exception: " + e);
   }
diff --git a/content/canvas/test/webgl/resources/js-test-pre.js b/content/canvas/test/webgl/resources/js-test-pre.js
index cd989f2e2d86..99ab54962188 100644
--- a/content/canvas/test/webgl/resources/js-test-pre.js
+++ b/content/canvas/test/webgl/resources/js-test-pre.js
@@ -469,9 +469,12 @@ function gc() {
 }
 
 function finishTest() {
+  testPassed("beginning of finishTest: " + (new Date().getTime()));
+
   successfullyParsed = true;
   var epilogue = document.createElement("script");
   epilogue.onload = function() {
+    testPassed("finishTest epilogue onload: " + (new Date().getTime()));
     if (window.nonKhronosFrameworkNotifyDone) {
       window.nonKhronosFrameworkNotifyDone();
     }
@@ -490,5 +493,6 @@ function finishTest() {
   }
   epilogue.src = basePath + "js-test-post.js";
   document.body.appendChild(epilogue);
+  testPassed("end of finishTest: " + (new Date().getTime()));
 }