diff --git a/core/block_render_svg.js b/core/block_render_svg.js
index b077d8197..7535db4a6 100644
--- a/core/block_render_svg.js
+++ b/core/block_render_svg.js
@@ -287,7 +287,7 @@ Blockly.BlockSvg.prototype.render = function(opt_bubble) {
       parentBlock.render(true);
     } else {
       // Top-most block.  Fire an event to allow scrollbars to resize.
-      Blockly.fireUiEvent(window, 'resize');
+      Blockly.asyncSvgResize(this.workspace);
     }
   }
   Blockly.Field.stopCache();
diff --git a/core/block_svg.js b/core/block_svg.js
index 8e1a954e0..d67e1acc1 100644
--- a/core/block_svg.js
+++ b/core/block_svg.js
@@ -257,7 +257,7 @@ Blockly.BlockSvg.terminateDrag_ = function() {
           Blockly.Events.setGroup(false);
       }, Blockly.BUMP_DELAY);
       // Fire an event to allow scrollbars to resize.
-      Blockly.fireUiEvent(window, 'resize');
+      Blockly.asyncSvgResize(this.workspace);
     }
   }
   Blockly.dragMode_ = Blockly.DRAG_NONE;
@@ -597,7 +597,7 @@ Blockly.BlockSvg.prototype.onMouseUp_ = function(e) {
     // Dropping a block on the trash can will usually cause the workspace to
     // resize to contain the newly positioned block.  Force a second resize
     // now that the block has been deleted.
-    Blockly.fireUiEvent(window, 'resize');
+    Blockly.asyncSvgResize(this.workspace);
   }
   if (Blockly.highlightedConnection_) {
     Blockly.highlightedConnection_.unhighlight();
diff --git a/core/blockly.js b/core/blockly.js
index aee1a20ca..17305ec83 100644
--- a/core/blockly.js
+++ b/core/blockly.js
@@ -132,12 +132,37 @@ Blockly.svgSize = function(svg) {
           height: svg.cachedHeight_};
 };
 
+/**
+ * Schedule a call to the resize handler.  Groups of simultaneous events (e.g.
+ * a tree of blocks being deleted) are merged into one call.
+ * @param {Blockly.WorkspaceSvg} workspace Any workspace in the SVG.
+ */
+Blockly.asyncSvgResize = function(workspace) {
+  if (Blockly.svgResizePending_) {
+    return;
+  }
+  if (!workspace) {
+    workspace = Blockly.getMainWorkspace();
+  }
+  Blockly.svgResizePending_ = true;
+  setTimeout(function() {Blockly.svgResize(workspace);}, 0);
+};
+
+/**
+ * Flag indicating a resize event is scheduled.
+ * Used to fire only one resize after multiple changes.
+ * @type {boolean}
+ * @private
+ */
+Blockly.svgResizePending_ = false;
+
 /**
  * Size the SVG image to completely fill its container.
  * Record the height/width of the SVG image.
  * @param {!Blockly.WorkspaceSvg} workspace Any workspace in the SVG.
  */
 Blockly.svgResize = function(workspace) {
+  Blockly.svgResizePending_ = false;
   var mainWorkspace = workspace;
   while (mainWorkspace.options.parentWorkspace) {
     mainWorkspace = mainWorkspace.options.parentWorkspace;
diff --git a/core/flyout.js b/core/flyout.js
index 1f05597f4..d943c91f0 100644
--- a/core/flyout.js
+++ b/core/flyout.js
@@ -433,7 +433,7 @@ Blockly.Flyout.prototype.show = function(xmlList) {
   this.filterForCapacity_();
 
   // Fire a resize event to update the flyout's scrollbar.
-  Blockly.fireUiEventNow(window, 'resize');
+  Blockly.svgResize(this.workspace_);
   this.reflowWrapper_ = this.reflow.bind(this);
   this.workspace_.addChangeListener(this.reflowWrapper_);
 };
@@ -578,7 +578,7 @@ Blockly.Flyout.prototype.reflow = function() {
     // Record the width for .getMetrics_ and .position.
     this.width_ = flyoutWidth;
     // Fire a resize event to update the flyout's scrollbar.
-    Blockly.fireUiEvent(window, 'resize');
+    Blockly.asyncSvgResize(this.workspace_);
   }
 };
 
diff --git a/core/inject.js b/core/inject.js
index a6abdb385..98935a5c9 100644
--- a/core/inject.js
+++ b/core/inject.js
@@ -263,7 +263,10 @@ Blockly.init_ = function(mainWorkspace) {
       });
 
   Blockly.bindEvent_(window, 'resize', null,
-                     function() {Blockly.svgResize(mainWorkspace);});
+      function() {
+        Blockly.hideChaff(true);
+        Blockly.asyncSvgResize(mainWorkspace);
+      });
 
   Blockly.inject.bindDocumentEvents_();
 
@@ -317,7 +320,7 @@ Blockly.inject.bindDocumentEvents_ = function() {
     // Some iPad versions don't fire resize after portrait to landscape change.
     if (goog.userAgent.IPAD) {
       Blockly.bindEvent_(window, 'orientationchange', document, function() {
-        Blockly.fireUiEvent(window, 'resize');
+        Blockly.asyncSvgResize();
       });
     }
   }
diff --git a/core/toolbox.js b/core/toolbox.js
index 8435ec5cf..2d765da6e 100644
--- a/core/toolbox.js
+++ b/core/toolbox.js
@@ -267,7 +267,7 @@ Blockly.Toolbox.prototype.populate_ = function(newTree) {
   }
 
   // Fire a resize event since the toolbox may have changed width and height.
-  Blockly.fireUiEvent(window, 'resize');
+  Blockly.asyncSvgResize(this.workspace_);
 };
 
 /**
@@ -442,7 +442,7 @@ Blockly.Toolbox.TreeNode = function(toolbox, html, opt_config, opt_domHelper) {
   goog.ui.tree.TreeNode.call(this, html, opt_config, opt_domHelper);
   if (toolbox) {
     var resize = function() {
-      Blockly.fireUiEvent(window, 'resize');
+      Blockly.asyncSvgResize(toolbox.workspace_);
     };
     // Fire a resize event since the toolbox may have changed width.
     goog.events.listen(toolbox.tree_,
diff --git a/core/utils.js b/core/utils.js
index 02d07df4f..aecc851b5 100644
--- a/core/utils.js
+++ b/core/utils.js
@@ -163,63 +163,6 @@ Blockly.unbindEvent_ = function(bindData) {
   return func;
 };
 
-/**
- * Fire a synthetic event synchronously.
- * @param {!EventTarget} node The event's target node.
- * @param {string} eventName Name of event (e.g. 'click').
- */
-Blockly.fireUiEventNow = function(node, eventName) {
-  // Remove the event from the anti-duplicate database.
-  var list = Blockly.fireUiEvent.DB_[eventName];
-  if (list) {
-    var i = list.indexOf(node);
-    if (i != -1) {
-      list.splice(i, 1);
-    }
-  }
-  // Create a UI event in a browser-compatible way.
-  if (typeof UIEvent == 'function') {
-    // W3
-    var evt = new UIEvent(eventName, {});
-  } else {
-    // MSIE
-    var evt = document.createEvent('UIEvent');
-    evt.initUIEvent(eventName, false, false, window, 0);
-  }
-  node.dispatchEvent(evt);
-};
-
-/**
- * Fire a synthetic event asynchronously.  Groups of simultaneous events (e.g.
- * a tree of blocks being deleted) are merged into one event.
- * @param {!EventTarget} node The event's target node.
- * @param {string} eventName Name of event (e.g. 'click').
- */
-Blockly.fireUiEvent = function(node, eventName) {
-  var list = Blockly.fireUiEvent.DB_[eventName];
-  if (list) {
-    if (list.indexOf(node) != -1) {
-      // This event is already scheduled to fire.
-      return;
-    }
-    list.push(node);
-  } else {
-    Blockly.fireUiEvent.DB_[eventName] = [node];
-  }
-  var fire = function() {
-    Blockly.fireUiEventNow(node, eventName);
-  };
-  setTimeout(fire, 0);
-};
-
-/**
- * Database of upcoming firing event types.
- * Used to fire only one event after multiple changes.
- * @type {!Object}
- * @private
- */
-Blockly.fireUiEvent.DB_ = {};
-
 /**
  * Don't do anything for this event, just halt propagation.
  * @param {!Event} e An event.
diff --git a/core/workspace_svg.js b/core/workspace_svg.js
index b44df8d4a..af0580b05 100644
--- a/core/workspace_svg.js
+++ b/core/workspace_svg.js
@@ -708,7 +708,7 @@ Blockly.WorkspaceSvg.prototype.cleanUp_ = function() {
   }
   Blockly.Events.setGroup(false);
   // Fire an event to allow scrollbars to resize.
-  Blockly.fireUiEvent(window, 'resize');
+  Blockly.asyncSvgResize(this);
 };
 
 /**
diff --git a/core/xml.js b/core/xml.js
index e6e3a1c5a..3e9e3cdc2 100644
--- a/core/xml.js
+++ b/core/xml.js
@@ -349,7 +349,7 @@ Blockly.Xml.domToBlock = function(xmlBlock, workspace) {
     }, 1);
     topBlock.updateDisabled();
     // Fire an event to allow scrollbars to resize.
-    Blockly.fireUiEvent(window, 'resize');
+    Blockly.asyncSvgResize(workspace);
   }
   Blockly.Events.enable();
   if (Blockly.Events.isEnabled()) {