Freeze global prototype chain per WebIDL

third_party/WebKit/LayoutTests/fast/dom/Window/window-custom-prototype-expected.txt

Index: third_party/WebKit/LayoutTests/fast/dom/Window/window-custom-prototype-expected.txt
diff --git a/third_party/WebKit/LayoutTests/fast/dom/Window/window-custom-prototype-expected.txt b/third_party/WebKit/LayoutTests/fast/dom/Window/window-custom-prototype-expected.txt
index 8065774dee767a829979558b208d186437702c7d..167350f4cf466087423c1ec477e586db80ae61c6 100644
--- a/third_party/WebKit/LayoutTests/fast/dom/Window/window-custom-prototype-expected.txt
+++ b/third_party/WebKit/LayoutTests/fast/dom/Window/window-custom-prototype-expected.txt
@@ -3,18 +3,18 @@ Test what happens when you set the window's prototype to various values.
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
 
 
-PASS __proto__ = window; __proto threw exception TypeError: Cyclic __proto__ value.

[Yuki, 2016/11/09 07:06:43]

Do we have the same test for non-global object at another place?
I think it's better to have a test to check if it throws when creating a cyclic
prototype chain.

If there is no similar test, would you mind to add a test for a non-global
object?

[Dan Ehrenberg, 2016/11/09 23:51:12]

Added a test at the end of this file for a similar circularity check. WDYT?

-PASS __proto__ = chainPointingBackToWindow; __proto__ threw exception TypeError: Cyclic __proto__ value.
+PASS __proto__ = window; __proto__ threw exception TypeError: Immutable prototype object '#<Window>' cannot have their prototype set.
+PASS __proto__ = chainPointingBackToWindow; __proto__ threw exception TypeError: Immutable prototype object '#<Window>' cannot have their prototype set.
 PASS __proto__ = 1; __proto__ is originalWindowPrototype
 PASS __proto__ = 'a string'; __proto__ is originalWindowPrototype
-PASS __proto__ = anotherObject; __proto__ is anotherObject
-PASS anotherObject.__proto__ = window; __proto__ threw exception TypeError: Cyclic __proto__ value.
-PASS __proto__ = 1; __proto__ is anotherObject
-PASS __proto__ = 'a string'; __proto__ is anotherObject
-PASS __proto__ = anotherObject; __proto__ is anotherObject
+PASS __proto__ = anotherObject; __proto__ threw exception TypeError: Immutable prototype object '#<Window>' cannot have their prototype set.
+PASS anotherObject.__proto__ = window; __proto__ is originalWindowPrototype
+PASS __proto__ = 1; __proto__ is originalWindowPrototype
+PASS __proto__ = 'a string'; __proto__ is originalWindowPrototype
+PASS __proto__ = anotherObject; __proto__ threw exception TypeError: Immutable prototype object '#<Window>' cannot have their prototype set.
 PASS __proto__ = originalWindowPrototype; __proto__ is originalWindowPrototype
 PASS anotherObject.__proto__ = window; anotherObject.__proto__ is window
-PASS __proto__ = null; window.__proto__ is undefined
+PASS __proto__ = null; __proto__ threw exception TypeError: Immutable prototype object '#<Window>' cannot have their prototype set.
 PASS successfullyParsed is true
 
 TEST COMPLETE