Update Custom Elements API to new names.

LayoutTests/fast/dom/custom/document-register-basic-expected.txt

Index: LayoutTests/fast/dom/custom/document-register-basic-expected.txt
diff --git a/LayoutTests/fast/dom/custom/document-register-basic-expected.txt b/LayoutTests/fast/dom/custom/document-register-basic-expected.txt
index 4eadbee60868ea9d5fbe62aacdf760a49e52844b..aecf9311aafd5cf41afd68c1bbba0105039079b5 100644
--- a/LayoutTests/fast/dom/custom/document-register-basic-expected.txt
+++ b/LayoutTests/fast/dom/custom/document-register-basic-expected.txt
@@ -1,4 +1,4 @@
-Testing document.register() basic behaviors.
+Testing document.registerElement() basic behaviors.
 
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
 
@@ -6,9 +6,9 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 PASS typeof fooConstructor is "function"
 PASS fooConstructor.prototype.__proto__ is HTMLElement.prototype
 PASS fooConstructor.prototype.thisIsPrototype is true
-PASS document.register("x-bad-a", HTMLElement) threw exception NotSupportedError: Failed to execute 'register' on 'Document': Registration failed for type 'x-bad-a'. The prototype is already in-use as an interface prototype object..
-PASS document.register("x-bad-b", fooConstructor) threw exception NotSupportedError: Failed to execute 'register' on 'Document': Registration failed for type 'x-bad-b'. The prototype is already in-use as an interface prototype object..
-PASS document.register("x-bad-c", { prototype: proto }) threw exception NotSupportedError: Failed to execute 'register' on 'Document': Registration failed for type 'x-bad-c'. Prototype constructor property is not configurable..
+PASS document.registerElement("x-bad-a", HTMLElement) threw exception NotSupportedError: Failed to execute 'registerElement' on 'Document': Registration failed for type 'x-bad-a'. The prototype is already in-use as an interface prototype object..
+PASS document.registerElement("x-bad-b", fooConstructor) threw exception NotSupportedError: Failed to execute 'registerElement' on 'Document': Registration failed for type 'x-bad-b'. The prototype is already in-use as an interface prototype object..
+PASS document.registerElement("x-bad-c", { prototype: proto }) threw exception NotSupportedError: Failed to execute 'registerElement' on 'Document': Registration failed for type 'x-bad-c'. Prototype constructor property is not configurable..
 PASS fooConstructor() threw exception TypeError: DOM object constructor cannot be called as a function..
 PASS createdFoo.__proto__ is fooConstructor.prototype
 PASS createdFoo.constructor is fooConstructor