Bug 1433566 part 2. Remove use of nsIDOMText from JS. r=mystor

MozReview-Commit-ID: LtAhn223y0s

devtools/server/actors/object.js

@@ -1869,7 +1869,8 @@ DebuggerServer.ObjectActorPreviewers.Object = [
       }
     } else if (obj.class == "Attr") {
       preview.value = hooks.createValueGrip(rawObj.value);
-    } else if (rawObj instanceof Ci.nsIDOMText ||
+    } else if (obj.class == "Text" ||
+               obj.class == "CDATASection" ||
                rawObj instanceof Ci.nsIDOMComment) {
       preview.textContent = hooks.createValueGrip(rawObj.textContent);
     }

dom/base/test/unit/test_range.js

@@ -340,6 +340,11 @@ function run_miscellaneous_tests() {
   getParsedDocument(filePath).then(do_miscellaneous_tests);
 }
 
+function isText(node) {
+  return node.nodeType == node.TEXT_NODE ||
+         node.nodeType == node.CDATA_SECTION_NODE;
+}
+
 function do_miscellaneous_tests(doc) {
   var tests = doc.getElementsByTagName("test");
 
@@ -360,7 +365,7 @@ function do_miscellaneous_tests(doc) {
   // Text range manipulation.
   if ((endOffset > startOffset) &&
       (startContainer == endContainer) &&
-      (startContainer instanceof Ci.nsIDOMText)) {
+      isText(startContainer)) {
     // Invalid start node
     try {
       baseRange.setStart(null, 0);
@@ -386,7 +391,7 @@ function do_miscellaneous_tests(doc) {
     }
   
     // Invalid index
-    var newOffset = startContainer instanceof Ci.nsIDOMText ?
+    var newOffset = isText(startContainer) ?
                       startContainer.nodeValue.length + 1 :
                       startContainer.childNodes.length + 1;
     try {