Enable pinch-zoom on the new login page.

extensions/browser/guest_view/web_view/web_view_constants.cc

 // 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.
 
 #include "extensions/browser/guest_view/web_view/web_view_constants.h"
 
 namespace webview {
 
 // Attributes.
 const char kAttributeAllowTransparency[] = "allowtransparency";
+const char kAttributeAllowScaling[] = "allowscaling";
 const char kAttributeName[] = "name";
 const char kAttributeSrc[] = "src";
 
 // API namespace.
 const char kAPINamespace[] = "webViewInternal";
 
 // API error messages.
 const char kAPILoadDataInvalidDataURL[] = "Invalid data URL \"%s\".";
 const char kAPILoadDataInvalidBaseURL[] = "Invalid base URL \"%s\".";
 const char kAPILoadDataInvalidVirtualURL[] = "Invalid virtual URL \"%s\".";
@@ skipping 85 matching lines @@
 
 // Miscellaneous.
 const char kMenuItemCommandId[] = "commandId";
 const char kMenuItemLabel[] = "label";
 const char kPersistPrefix[] = "persist:";
 const char kStoragePartitionId[] = "partition";
 const unsigned int kMaxOutstandingPermissionRequests = 1024;
 const int kInvalidPermissionRequestID = 0;
 
 }  // namespace webview