Seperate DOMVisualViewport from Blink's VisualViewport class

third_party/WebKit/LayoutTests/fast/dom/Window/property-access-on-cached-window-after-frame-removed-and-gced-expected.txt

 CONSOLE WARNING: line 104: 'window.webkitStorageInfo' is deprecated. Please use 'navigator.webkitTemporaryStorage' or 'navigator.webkitPersistentStorage' instead.
 CONSOLE WARNING: line 104: 'webkitIndexedDB' is deprecated. Please use 'indexedDB' instead.
 CONSOLE WARNING: line 104: 'Performance.onwebkitresourcetimingbufferfull' is deprecated. Please use 'Performance.onresourcetimingbufferfull' instead.
 Tests property access on a cached DOMWindow after the associated frame is removed from a web page and garbage collected. Test should not crash and properties should be set to sane defaults.
 
 On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
 
 
 FAIL childWindow.applicationCache.oncached should be null. Threw exception TypeError: Cannot read property 'oncached' of null
 FAIL childWindow.applicationCache.onchecking should be null. Threw exception TypeError: Cannot read property 'onchecking' of null
@@ skipping 197 matching lines @@
 PASS childWindow.scrollY is 0
 PASS childWindow.scrollbars.visible is false
 FAIL childWindow.speechSynthesis.onvoiceschanged should be null. Threw exception TypeError: Cannot read property 'onvoiceschanged' of null
 FAIL childWindow.speechSynthesis.paused should be false. Threw exception TypeError: Cannot read property 'paused' of null
 FAIL childWindow.speechSynthesis.pending should be false. Threw exception TypeError: Cannot read property 'pending' of null
 FAIL childWindow.speechSynthesis.speaking should be false. Threw exception TypeError: Cannot read property 'speaking' of null
 PASS childWindow.status is ''
 PASS childWindow.statusbar.visible is false
 PASS childWindow.styleMedia.type is ''
 PASS childWindow.toolbar.visible is false
+FAIL childWindow.visualViewport.clientHeight should be 0. Threw exception TypeError: Cannot read property 'clientHeight' of null

[bokan, 2016/06/16 07:22:43]

Why do some other properties not throw? e.g. childWindow.performance

[ymalik, 2016/06/20 15:52:56]

I think it has to do with whether or not a property is on the OilPan heap. If a
property is a Member<T> of Window, it is GC-ed and throws an exception (e.g
speechSynthesis, visualViewport).

+FAIL childWindow.visualViewport.clientWidth should be 0. Threw exception TypeError: Cannot read property 'clientWidth' of null
+FAIL childWindow.visualViewport.pageScale should be 0. Threw exception TypeError: Cannot read property 'pageScale' of null
+FAIL childWindow.visualViewport.scrollLeft should be 0. Threw exception TypeError: Cannot read property 'scrollLeft' of null
+FAIL childWindow.visualViewport.scrollTop should be 0. Threw exception TypeError: Cannot read property 'scrollTop' of null
 PASS successfullyParsed is true
 
 TEST COMPLETE