Add an optional set_hook argument to defineProperty.

chrome/browser/resources/shared/js/cr_test.html

Index: chrome/browser/resources/shared/js/cr_test.html
diff --git a/chrome/browser/resources/shared/js/cr_test.html b/chrome/browser/resources/shared/js/cr_test.html
index b20281c1f8d1e74a71b76b18bc2f246bdcb0d7ba..f17e1b481aff93027d91c26a5bd67fd3beeec300 100644
--- a/chrome/browser/resources/shared/js/cr_test.html
+++ b/chrome/browser/resources/shared/js/cr_test.html
@@ -39,22 +39,27 @@ function testDefinePropertyOnClass() {
   cr.defineProperty(C, 'test');
 
   var obj = new C;
+  assertUndefined(obj.test);
+
   obj.test = 1;
   assertEquals(1, obj.test);
   assertEquals(1, obj.test_);
 }
 
-function testDefinePropertyWithDefault() {
+function testDefinePropertyWithSetter() {
   var obj = new EventTarget;
 
-  cr.defineProperty(obj, 'test', null, 1);
-
-  assertEquals(1, obj.test);
-  assertEquals(1, obj.test_);
-
+  var hit = false;
+  function onTestSet(value, oldValue) {
+    assertEquals(obj, this);
+    assertEquals(2, this.test);
+    assertUndefined(oldValue);
+    assertEquals(2, value);
+    hit = true;
+  }
+  cr.defineProperty(obj, 'test', cr.PropertyKind.JS, onTestSet); 
   obj.test = 2;
-  assertEquals(2, obj.test);
-  assertEquals(2, obj.test_);
+  assertTrue(hit);
 }
 
 function testDefinePropertyEvent() {
@@ -82,20 +87,20 @@ function testDefinePropertyEvent() {
 
 function testDefinePropertyEventWithDefault() {
   var obj = new EventTarget;
-  cr.defineProperty(obj, 'test', cr.PropertyKind.JS, 1);
+  cr.defineProperty(obj, 'test', cr.PropertyKind.JS);
 
   var count = 0;
   function f(e) {
     assertEquals('testChange', e.type);
     assertEquals('test', e.propertyName);
-    assertEquals(1, e.oldValue);
+    assertUndefined(e.oldValue);
     assertEquals(2, e.newValue);
     count++;
   }
 
   obj.addEventListener('testChange', f);
 
-  obj.test = 1;
+  obj.test = undefined;
   assertEquals('Should not have called the property change listener', 0, count);
 
   obj.test = 2;
@@ -119,62 +124,45 @@ function testDefinePropertyAttrOnClass() {
   var obj = document.createElement('button');
   cr.defineProperty(HTMLButtonElement, 'test', cr.PropertyKind.ATTR);
 
+  assertEquals(null, obj.test);
+
   obj.test = 'a';
   assertEquals('a', obj.test);
   assertEquals('a', obj.getAttribute('test'));
 }
 
-function testDefinePropertyAttrWithDefault() {
+function testDefinePropertyAttrWithSetter() {
   var obj = document.createElement('div');
-  cr.defineProperty(obj, 'test', cr.PropertyKind.ATTR, 'a');
-
-  assertEquals('a', obj.test);
-  assertFalse(obj.hasAttribute('test'));
 
+  var hit = false;
+  function onTestSet(value, oldValue) {
+    assertEquals(obj, this);
+    assertEquals(null, oldValue);
+    assertEquals('b', value);
+    assertEquals('b', this.test);
+    hit = true;
+  }
+  cr.defineProperty(obj, 'test', cr.PropertyKind.ATTR, onTestSet);
   obj.test = 'b';
-  assertEquals('b', obj.test);
-  assertEquals('b', obj.getAttribute('test'));
+  assertTrue(hit);
 }
 
 function testDefinePropertyAttrEvent() {
   var obj = document.createElement('div');
   cr.defineProperty(obj, 'test', cr.PropertyKind.ATTR);
-  obj.test = 'a';
-
-  var count = 0;
-  function f(e) {
-    assertEquals('testChange', e.type);
-    assertEquals('test', e.propertyName);
-    assertEquals('a', e.oldValue);
-    assertEquals('b', e.newValue);
-    count++;
-  }
-
-  obj.addEventListener('testChange', f);
-  obj.test = 'b';
-  assertEquals('b', obj.test);
-  assertEquals('Should have called the property change listener', 1, count);
-
-  obj.test = 'b';
-  assertEquals(1, count);
-}
-
-function testDefinePropertyAttrEventWithDefault() {
-  var obj = document.createElement('div');
-  cr.defineProperty(obj, 'test', cr.PropertyKind.ATTR, 'a');
 
   var count = 0;
   function f(e) {
     assertEquals('testChange', e.type);
     assertEquals('test', e.propertyName);
-    assertEquals('a', e.oldValue);
+    assertEquals(null, e.oldValue);
     assertEquals('b', e.newValue);
     count++;
   }
 
   obj.addEventListener('testChange', f);
 
-  obj.test = 'a';
+  obj.test = null;
   assertEquals('Should not have called the property change listener', 0, count);
 
   obj.test = 'b';
@@ -223,6 +211,21 @@ function testDefinePropertyBoolAttrEvent() {
   assertEquals(1, count);
 }
 
+function testDefinePropertyBoolAttrEvent() {
+  var obj = document.createElement('div');
+  var hit = false;
+  function onTestSet(value, oldValue) {
+    assertEquals(obj, this);
+    assertTrue(this.test);
+    assertFalse(oldValue);
+    assertTrue(value);
+    hit = true;
+  }
+  cr.defineProperty(obj, 'test', cr.PropertyKind.BOOL_ATTR, onTestSet);
+  obj.test = true;
+  assertTrue(hit);
+}
+
 function testAddSingletonGetter() {
   function Foo() {};
   cr.addSingletonGetter(Foo);