From 0e982433eb94391b3e9f6838d9b8fbf9bb31abf9 Mon Sep 17 00:00:00 2001
From: Jason Bedard <jason+github@jbedard.ca>
Date: Sat, 18 Jul 2015 11:27:11 -0700
Subject: Data: avoid using delete on DOM nodes

Closes gh-2479
---
 src/data/Data.js    | 18 +++++++++++++-----
 src/manipulation.js | 10 ++++++++--
 2 files changed, 21 insertions(+), 7 deletions(-)

(limited to 'src')

diff --git a/src/data/Data.js b/src/data/Data.js
index e0d1eadcd..625d203cf 100644
--- a/src/data/Data.js
+++ b/src/data/Data.js
@@ -20,13 +20,12 @@ Data.prototype = {
 		if ( owner.nodeType ) {
 			owner[ this.expando ] = value;
 
-		// Otherwise secure it in a non-enumerable, non-writable property
-		// configurability must be true to allow the property to be
-		// deleted with the delete operator
+		// Otherwise secure it in a non-enumerable property
+		// configurable must be true to allow the property to be
+		// deleted when data is removed
 		} else {
 			Object.defineProperty( owner, this.expando, {
 				value: value,
-				writable: true,
 				configurable: true
 			} );
 		}
@@ -144,7 +143,16 @@ Data.prototype = {
 
 		// Remove the expando if there's no more data
 		if ( key === undefined || jQuery.isEmptyObject( cache ) ) {
-			delete owner[ this.expando ];
+
+			// Support: Chrome <= 35-45+
+			// Webkit & Blink performance suffers when deleting properties
+			// from DOM nodes, so set to undefined instead
+			// https://code.google.com/p/chromium/issues/detail?id=378607
+			if ( owner.nodeType ) {
+				owner[ this.expando ] = undefined;
+			} else {
+				delete owner[ this.expando ];
+			}
 		}
 	},
 	hasData: function( owner ) {
diff --git a/src/manipulation.js b/src/manipulation.js
index b85ef1824..ceb970cbd 100644
--- a/src/manipulation.js
+++ b/src/manipulation.js
@@ -290,10 +290,16 @@ jQuery.extend( {
 							}
 						}
 					}
-					delete elem[ dataPriv.expando ];
+
+					// Support: Chrome <= 35-45+
+					// Assign undefined instead of using delete, see Data#remove
+					elem[ dataPriv.expando ] = undefined;
 				}
 				if ( elem[ dataUser.expando ] ) {
-					delete elem[ dataUser.expando ];
+
+					// Support: Chrome <= 35-45+
+					// Assign undefined instead of using delete, see Data#remove
+					elem[ dataUser.expando ] = undefined;
 				}
 			}
 		}
-- 
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