Use registry for connection checker

core/connection_checker.js

@@ -13,6 +13,8 @@
 
 goog.provide('Blockly.ConnectionChecker');
 
+goog.require('Blockly.registry');
+
 goog.requireType('Blockly.Connection');
 goog.requireType('Blockly.IConnectionChecker');
 
@@ -278,3 +280,6 @@ Blockly.ConnectionChecker.prototype.canConnectToPrevious_ = function(a, b) {
   // marker is in the middle of a stack, it won't work.
   return !targetBlock.getPreviousBlock();
 };
+
+Blockly.registry.register(Blockly.registry.Type.CONNECTION_CHECKER,
+    Blockly.registry.DEFAULT, Blockly.ConnectionChecker);

core/registry.js

@@ -15,6 +15,7 @@ goog.provide('Blockly.registry');
 
 goog.requireType('Blockly.blockRendering.Renderer');
 goog.requireType('Blockly.Field');
+goog.requireType('Blockly.IConnectionChecker');
 goog.requireType('Blockly.IToolbox');
 goog.requireType('Blockly.Theme');
 goog.requireType('Blockly.utils.toolbox');
@@ -70,6 +71,10 @@ Blockly.registry.Type.TOOLBOX = new Blockly.registry.Type('toolbox');
 /** @type {!Blockly.registry.Type<Blockly.Theme>} */
 Blockly.registry.Type.THEME = new Blockly.registry.Type('theme');
 
+/** @type {!Blockly.registry.Type<Blockly.IConnectionChecker>} */
+Blockly.registry.Type.CONNECTION_CHECKER =
+    new Blockly.registry.Type('connectionChecker');
+
 /**
  * Registers a class based on a type and name.
  * @param {string|Blockly.registry.Type<T>} type The type of the plugin.

core/workspace.js

@@ -44,11 +44,13 @@ Blockly.Workspace = function(opt_options) {
   /** @type {number} */
   this.toolboxPosition = this.options.toolboxPosition;
 
+  var connectionCheckerClass = Blockly.registry.getClassFromOptions(
+      Blockly.registry.Type.CONNECTION_CHECKER, this.options);
   /**
    * An object that encapsulates logic for safety, type, and dragging checks.
    * @type {!Blockly.IConnectionChecker}
    */
-  this.connectionChecker = new Blockly.ConnectionChecker();
+  this.connectionChecker = new connectionCheckerClass(this);
 
   /**
    * @type {!Array.<!Blockly.Block>}