Got rid of the internal copies of webview attributes.

extensions/test/data/web_view/apitest/main.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 var embedder = {};
 
 // TODO(lfg) Move these functions to a common js.
 embedder.setUp_ = function(config) {
   if (!config || !config.testServer) {
     return;
@@ skipping 53 matching lines @@
 };
 
 
 // Tests begin.
 
 // This test verifies that the allowtransparency property cannot be changed
 // once set. The attribute can only be deleted.
 function testAllowTransparencyAttribute() {
   var webview = document.createElement('webview');
   webview.src = 'data:text/html,webview test';
+  embedder.test.assertFalse(webview.hasAttribute('allowtransparency'));
+  embedder.test.assertFalse(webview.allowtransparency);
   webview.allowtransparency = true;
 
   webview.addEventListener('loadstop', function(e) {
     embedder.test.assertTrue(webview.hasAttribute('allowtransparency'));
+    embedder.test.assertTrue(webview.allowtransparency);
     webview.allowtransparency = false;
+    embedder.test.assertFalse(webview.hasAttribute('allowtransparency'));
+    embedder.test.assertFalse(webview.allowtransparency);
+    webview.allowtransparency = '';
+    embedder.test.assertFalse(webview.hasAttribute('allowtransparency'));
+    embedder.test.assertFalse(webview.allowtransparency);
+    webview.allowtransparency = 'some string';
+    embedder.test.assertTrue(webview.hasAttribute('allowtransparency'));
     embedder.test.assertTrue(webview.allowtransparency);
-    embedder.test.assertTrue(webview.hasAttribute('allowtransparency'));
-    webview.removeAttribute('allowtransparency');
-    embedder.test.assertFalse(webview.allowtransparency);
     embedder.test.succeed();
   });
 
   document.body.appendChild(webview);
 }
 
 function testAPIMethodExistence() {
   var apiMethodsToCheck = [
     'back',
     'find',
@@ skipping 1182 matching lines @@
       embedder.test.succeed();
     };
 
     webview.setAttribute('src', 'data:text/html,next navigation');
   });
 
   webview.setAttribute('src', 'data:text/html,trigger navigation');
   document.body.appendChild(webview);
 }
 
-// This test verifies that setting the partition attribute after the src has
-// been set raises an exception.
-function testPartitionRaisesException() {
+// This test verifies that the partion attribute cannot be changed after the src
+// has been set.
+function testPartitionChangeAfterNavigation() {
   var webview = document.createElement('webview');
   var partitionAttribute = arguments.callee.name;
   webview.setAttribute('partition', partitionAttribute);
 
   var loadstopHandler = function(e) {
-    try {
-      webview.partition = 'illegal';
-      embedder.test.fail();
-    } catch (e) {
-      embedder.test.assertEq(partitionAttribute, webview.partition);
-      embedder.test.succeed();
-    }
+    webview.partition = 'illegal';
+    embedder.test.assertEq(partitionAttribute, webview.partition);
+    embedder.test.succeed();
   };
   webview.addEventListener('loadstop', loadstopHandler);
 
   webview.setAttribute('src', 'data:text/html,trigger navigation');
   document.body.appendChild(webview);
 }
 
 // This test verifies that removing partition attribute after navigation does
 // not work, i.e. the partition remains the same.
 function testPartitionRemovalAfterNavigationFails() {
@@ skipping 390 matching lines @@
   'testNavigateAfterResize': testNavigateAfterResize,
   'testNavigationToExternalProtocol': testNavigationToExternalProtocol,
   'testNavOnConsecutiveSrcAttributeChanges':
       testNavOnConsecutiveSrcAttributeChanges,
   'testNavOnSrcAttributeChange': testNavOnSrcAttributeChange,
   'testNewWindow': testNewWindow,
   'testNewWindowNoPreventDefault': testNewWindowNoPreventDefault,
   'testNewWindowNoReferrerLink': testNewWindowNoReferrerLink,
   'testNewWindowTwoListeners': testNewWindowTwoListeners,
   'testOnEventProperties': testOnEventProperties,
-  'testPartitionRaisesException': testPartitionRaisesException,
+  'testPartitionChangeAfterNavigation': testPartitionChangeAfterNavigation,
   'testPartitionRemovalAfterNavigationFails':
       testPartitionRemovalAfterNavigationFails,
   'testReassignSrcAttribute': testReassignSrcAttribute,
   'testReload': testReload,
   'testReloadAfterTerminate': testReloadAfterTerminate,
   'testRemoveSrcAttribute': testRemoveSrcAttribute,
   'testRemoveWebviewAfterNavigation': testRemoveWebviewAfterNavigation,
   'testRemoveWebviewOnExit': testRemoveWebviewOnExit,
   'testResizeWebviewResizesContent': testResizeWebviewResizesContent,
   'testTerminateAfterExit': testTerminateAfterExit,
   'testWebRequestAPI': testWebRequestAPI,
   'testWebRequestAPIWithHeaders': testWebRequestAPIWithHeaders,
   'testWebRequestAPIExistence': testWebRequestAPIExistence,
   'testWebRequestAPIGoogleProperty': testWebRequestAPIGoogleProperty
 };
 
 onload = function() {
   chrome.test.getConfig(function(config) {
     embedder.setUp_(config);
     chrome.test.sendMessage('LAUNCHED');
   });
 };