Let Selection.collapse remember a raw Position instead of a canonicalized one.

LayoutTests/editing/editing.js

 //-------------------------------------------------------------------------------------------------------
 // Java script library to run editing layout tests
 
 var commandCount = 1;
 var commandDelay = window.location.search.substring(1);
 if (commandDelay == '')
     commandDelay = 0;
 var selection = window.getSelection();
 
 //-------------------------------------------------------------------------------------------------------
@@ skipping 875 matching lines @@
         i++;
         if (i < queue.length)
             setTimeout(runCommand, commandDelay);
         else if (window.testRunner)
             testRunner.notifyDone();
     }
     
     window.queueCommand = queueCommand;
 })();
 
+function focusOnFirstTextInTestElementIfExists() {
+    var elem = document.getElementById("test");
+    var selection = window.getSelection();
+    if (elem) {
+        var traverse = function (node, offset, condition) {
+            var obj = condition(node, offset);
+            if (obj)
+                return obj;
+
+            var children = node.childNodes;
+            var len = children.length;
+            for (var i = 0; i < len; i++) {
+                var child = children[i];
+                obj = traverse(child, i, condition);
+                if (obj)
+                    return obj;
+            }
+            return null;
+        }
+
+        var firstVisiblePosition = traverse(elem, 0, function (node, offset) {
+            if (node.nodeName == '#text') {
+                offset = 0;
+                while (offset < node.textContent.length && node.textContent[offset] == '\n')
+                    offset++;
+                return { 'node': node, 'offset': offset };
+            }
+
+            if (node.nodeName == 'BR' || node.nodeName == 'IMG')
+                return { 'node': node.parentNode, 'offset': offset };
+
+            return null;
+        });
+
+        if (firstVisiblePosition)
+            selection.collapse(firstVisiblePosition.node, firstVisiblePosition.offset);
+        else
+            selection.collapse(elem, 0);
+    } else {
+        selection.removeAllRanges();
+    }
+}
+
 function runEditingTest() {
     if (window.testRunner)
         testRunner.dumpEditingCallbacks();
 
-    var elem = document.getElementById("test");
-    var selection = window.getSelection();
-    if (elem)
-        selection.collapse(elem, 0);
-    else
-        selection.removeAllRanges();
+    focusOnFirstTextInTestElementIfExists();
+
     editingTest();
 }
 
 var dumpAsText = false;
 var elementsForDumpingMarkupList = [document.createElement('ol')];
 
 function runDumpAsTextEditingTest(enableCallbacks) {
     if (window.testRunner) {
          testRunner.dumpAsText();
          if (enableCallbacks)
             testRunner.dumpEditingCallbacks();
      }
 
     dumpAsText = true;
 
-    var elem = document.getElementById("test");
-    var selection = window.getSelection();
-    if (elem)
-        selection.collapse(elem, 0);
-    else
-        selection.removeAllRanges();
+    focusOnFirstTextInTestElementIfExists();
+
     editingTest();
 
     for (var i = 0; i < elementsForDumpingMarkupList.length; i++)
         document.body.appendChild(elementsForDumpingMarkupList[i]);
 }
 
 function debugForDumpAsText(name) {
     if (dumpAsText && document.getElementById("root")) {
         var newItem = document.createElement('li');
         newItem.appendChild(document.createTextNode(name+": "+document.getElementById("root").innerHTML));
@@ skipping 49 matching lines @@
 function executeCommand(command,arg1,arg2) {
     if (commandDelay > 0) {
         queueCommand(runCommand, commandCount * commandDelay);
         commandCount++;
     }
     else {
         runCommand(command,arg1,arg2);
     }
 }