diff --git a/core/mutator.js b/core/mutator.js
index 852f49b41..19a0fe86b 100644
--- a/core/mutator.js
+++ b/core/mutator.js
@@ -118,32 +118,20 @@ Blockly.Mutator.prototype.createEditor_ = function() {
     var quarkXml = null;
   }
   var workspaceOptions = {
-    horizontalLayout: false,
     languageTree: quarkXml,
     parentWorkspace: this.block_.workspace,
     pathToMedia: this.block_.workspace.options.pathToMedia,
     RTL: this.block_.RTL,
-    hasCategories: false,
     toolboxPosition: this.block_.RTL ? Blockly.TOOLBOX_AT_RIGHT :
         Blockly.TOOLBOX_AT_LEFT,
+    horizontalLayout: false,
     getMetrics: this.getFlyoutMetrics_.bind(this),
     setMetrics: null
   };
   this.workspace_ = new Blockly.WorkspaceSvg(workspaceOptions);
   this.workspace_.isMutator = true;
-  //this.flyout_ = new Blockly.Flyout();
-  //this.flyout_.autoClose = false;
-  //this.svgDialog_.appendChild(this.flyout_.createDom());
   this.svgDialog_.appendChild(
-    this.workspace_.createDom('blocklyMutatorBackground'));
-
-  //when mutator bubble is clicked, do not close mutator
-  Blockly.bindEvent_(this.svgDialog_, 'mousedown', this.svgDialog_,
-      function(e) {
-        e.preventDefault();
-        e.stopPropagation();
-      });
-
+      this.workspace_.createDom('blocklyMutatorBackground'));
   return this.svgDialog_;
 };
 
@@ -177,12 +165,7 @@ Blockly.Mutator.prototype.updateEditable = function() {
  */
 Blockly.Mutator.prototype.resizeBubble_ = function() {
   var doubleBorderWidth = 2 * Blockly.Bubble.BORDER_WIDTH;
-  try {
-    var workspaceSize = this.workspace_.getCanvas().getBBox();
-  } catch (e) {
-    // Firefox has trouble with hidden elements (Bug 528969).
-    return;
-  }
+  var workspaceSize = this.workspace_.getCanvas().getBBox();
   var width;
   if (this.block_.RTL) {
     width = -workspaceSize.x;
diff --git a/core/scrollbar.js b/core/scrollbar.js
index 5fae5e13a..da2dd942d 100644
--- a/core/scrollbar.js
+++ b/core/scrollbar.js
@@ -125,6 +125,7 @@ Blockly.ScrollbarPair.prototype.resize = function() {
       this.oldHostMetrics_.absoluteTop != hostMetrics.absoluteTop) {
     this.corner_.setAttribute('y', this.hScroll.position_.y);
   }
+
   // Cache the current metrics to potentially short-cut the next resize event.
   this.oldHostMetrics_ = hostMetrics;
 };
diff --git a/core/workspace.js b/core/workspace.js
index deac51b6f..a8e97c04b 100644
--- a/core/workspace.js
+++ b/core/workspace.js
@@ -117,8 +117,6 @@ Blockly.Workspace.SCAN_ANGLE = 3;
  * @param {!Blockly.Block} block Block to remove.
  */
 Blockly.Workspace.prototype.addTopBlock = function(block) {
-  if (block.workspace == Blockly.mainWorkspace) //Do not reset arrangements for the flyout
-    this.resetArrangements();
   this.topBlocks_.push(block);
   if (this.isFlyout) {
     // This is for the (unlikely) case where you have a variable in a block in
@@ -138,8 +136,6 @@ Blockly.Workspace.prototype.addTopBlock = function(block) {
  * @param {!Blockly.Block} block Block to remove.
  */
 Blockly.Workspace.prototype.removeTopBlock = function(block) {
-  if (block.workspace == Blockly.mainWorkspace) //Do not reset arrangements for the flyout
-    this.resetArrangements();
   var found = false;
   for (var child, i = 0; child = this.topBlocks_[i]; i++) {
     if (child == block) {
@@ -160,7 +156,6 @@ Blockly.Workspace.prototype.removeTopBlock = function(block) {
  * @return {!Array.<!Blockly.Block>} The top-level block objects.
  */
 Blockly.Workspace.prototype.getTopBlocks = function(ordered) {
-  var start = new Date().getTime(); //*** lyn instrumentation
   // Copy the topBlocks_ list.
   var blocks = [].concat(this.topBlocks_);
   if (ordered && blocks.length > 1) {
@@ -174,10 +169,6 @@ Blockly.Workspace.prototype.getTopBlocks = function(ordered) {
       return (aXY.y + offset * aXY.x) - (bXY.y + offset * bXY.x);
     });
   }
-  var stop = new Date().getTime(); //*** lyn instrumentation
-  var timeDiff = stop - start; //*** lyn instrumentation
-  Blockly.Instrument.stats.getTopBlocksCalls++;
-  Blockly.Instrument.stats.getTopBlocksTime += timeDiff;
   return blocks;
 };
 
diff --git a/core/workspace_svg.js b/core/workspace_svg.js
index 371f6008a..f17cd3d86 100644
--- a/core/workspace_svg.js
+++ b/core/workspace_svg.js
@@ -947,7 +947,13 @@ Blockly.WorkspaceSvg.prototype.showContextMenu_ = function(e) {
     var expandOption = {enabled: hasCollapsedBlocks};
     expandOption.text = Blockly.Msg.EXPAND_ALL;
     expandOption.callback = function() {
-      toggleOption(false);
+      Blockly.Instrument.initializeStats('expandAllCollapsedBlocks');
+      Blockly.Instrument.timer(
+        function() { toggleOption(false); },
+        function(result, timeDiff) {
+          Blockly.Instrument.stats.totalTime = timeDiff;
+          Blockly.Instrument.displayStats('expandAllCollapsedBlocks');
+        });
     };
     menuOptions.push(expandOption);
   }
diff --git a/core/xml.js b/core/xml.js
index cd94880d8..2567560cd 100644
--- a/core/xml.js
+++ b/core/xml.js
@@ -156,7 +156,7 @@ Blockly.Xml.blockToDom = function(block) {
   var nextBlock = block.getNextBlock();
   if (nextBlock) {
     var container = goog.dom.createDom('next', null,
-      Blockly.Xml.blockToDom(nextBlock));
+        Blockly.Xml.blockToDom(nextBlock));
     element.appendChild(container);
   }
   var shadow = block.nextConnection && block.nextConnection.getShadowDom();