diff -r 000000000000 -r 6474c204b198 browser/devtools/sourceeditor/codemirror/fold/foldcode.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/sourceeditor/codemirror/fold/foldcode.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,86 @@
+(function() {
+  "use strict";
+
+  function doFold(cm, pos, options, force) {
+    var finder = options && (options.call ? options : options.rangeFinder);
+    if (!finder) finder = CodeMirror.fold.auto;
+    if (typeof pos == "number") pos = CodeMirror.Pos(pos, 0);
+    var minSize = options && options.minFoldSize || 0;
+
+    function getRange(allowFolded) {
+      var range = finder(cm, pos);
+      if (!range || range.to.line - range.from.line < minSize) return null;
+      var marks = cm.findMarksAt(range.from);
+      for (var i = 0; i < marks.length; ++i) {
+        if (marks[i].__isFold && force !== "fold") {
+          if (!allowFolded) return null;
+          range.cleared = true;
+          marks[i].clear();
+        }
+      }
+      return range;
+    }
+
+    var range = getRange(true);
+    if (options && options.scanUp) while (!range && pos.line > cm.firstLine()) {
+      pos = CodeMirror.Pos(pos.line - 1, 0);
+      range = getRange(false);
+    }
+    if (!range || range.cleared || force === "unfold") return;
+
+    var myWidget = makeWidget(options);
+    CodeMirror.on(myWidget, "mousedown", function() { myRange.clear(); });
+    var myRange = cm.markText(range.from, range.to, {
+      replacedWith: myWidget,
+      clearOnEnter: true,
+      __isFold: true
+    });
+    myRange.on("clear", function(from, to) {
+      CodeMirror.signal(cm, "unfold", cm, from, to);
+    });
+    CodeMirror.signal(cm, "fold", cm, range.from, range.to);
+  }
+
+  function makeWidget(options) {
+    var widget = (options && options.widget) || "\u2194";
+    if (typeof widget == "string") {
+      var text = document.createTextNode(widget);
+      widget = document.createElement("span");
+      widget.appendChild(text);
+      widget.className = "CodeMirror-foldmarker";
+    }
+    return widget;
+  }
+
+  // Clumsy backwards-compatible interface
+  CodeMirror.newFoldFunction = function(rangeFinder, widget) {
+    return function(cm, pos) { doFold(cm, pos, {rangeFinder: rangeFinder, widget: widget}); };
+  };
+
+  // New-style interface
+  CodeMirror.defineExtension("foldCode", function(pos, options, force) {
+    doFold(this, pos, options, force);
+  });
+
+  CodeMirror.commands.fold = function(cm) {
+    cm.foldCode(cm.getCursor());
+  };
+
+  CodeMirror.registerHelper("fold", "combine", function() {
+    var funcs = Array.prototype.slice.call(arguments, 0);
+    return function(cm, start) {
+      for (var i = 0; i < funcs.length; ++i) {
+        var found = funcs[i](cm, start);
+        if (found) return found;
+      }
+    };
+  });
+
+  CodeMirror.registerHelper("fold", "auto", function(cm, start) {
+    var helpers = cm.getHelpers(start, "fold");
+    for (var i = 0; i < helpers.length; i++) {
+      var cur = helpers[i](cm, start);
+      if (cur) return cur;
+    }
+  });
+})();