I added blocking bugs for ClipboardEvent, DeviceMotionEvent, DeviceOrientationEvent, Document, and FontFaceSet. The rest I don't recall noticing, and we'll have to look for bugs and file if none exist.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/84f416819a18138cdf94d39f7f0e313fb310a94a

commit 84f416819a18138cdf94d39f7f0e313fb310a94a
Author: lunalu <lunalu@chromium.org>
Date: Mon Jan 16 22:03:39 2017

Expose FontFaceSetLoadEvent and add a constructor for it

Intent to ship: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/AlZEmkeiKg8

BUG=673664

Review-Url: https://codereview.chromium.org/2579513005
Cr-Commit-Position: refs/heads/master@{#443950}

[add] https://crrev.com/84f416819a18138cdf94d39f7f0e313fb310a94a/third_party/WebKit/LayoutTests/fast/css/fontfacesetloadevent-constructor.html
[modify] https://crrev.com/84f416819a18138cdf94d39f7f0e313fb310a94a/third_party/WebKit/LayoutTests/platform/linux/virtual/stable/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/84f416819a18138cdf94d39f7f0e313fb310a94a/third_party/WebKit/LayoutTests/platform/win/virtual/stable/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/84f416819a18138cdf94d39f7f0e313fb310a94a/third_party/WebKit/LayoutTests/virtual/stable/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/84f416819a18138cdf94d39f7f0e313fb310a94a/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/84f416819a18138cdf94d39f7f0e313fb310a94a/third_party/WebKit/Source/core/css/FontFaceSetLoadEvent.idl

 FontFaceSet 
 DeviceOrientationEvent 
 PerformanceObserver
 Animation 
 DocumentTimeline 
 VRLayer 
 IntersectionObserverEntry
 ResizeObserverEntry  
 CustomEvent 
 Document 
 DeviceMotionEvent 
 ExtendableMessageEvent
 Path2D missing Constructor(sequence<Path2D> paths, optional CanvasFillRule fillRule = "nonzero")
USBOutTransferResult
USBIsochronousOutTransferResult
USBIsochronousOutTransferPacket
USBIsochronousInTransferResult
USBIsochronousInTransferPacket
USBInTransferResult

Fixed:
 FontFaceSetLoadEvent 
 DOMMatrixReadOnly 
 DOMMatrix
 MediaStreamAudioDestinationNode  
 PresentationRequest 
 ClipboardEvent 
 SpeechSynthesisUtterance  TODO in spec Constructor, Constructor(text) => Constructor(optional text)  
 IntersectionObserver  TODO CustomConstructor => Constructor
 MessageChannel TODO CustomConstructor => Constructor
 MutationObserver TODO CustomConstructor => Constructor

These have been fixed:
 FontFaceSetLoadEvent 
 DOMMatrixReadOnly 
 DOMMatrix
 MediaStreamAudioDestinationNode  
 PresentationRequest 
 ClipboardEvent 
 SpeechSynthesisUtterance  TODO in spec Constructor, Constructor(text) => Constructor(optional text)  
 IntersectionObserver  TODO CustomConstructor => Constructor
 MessageChannel TODO CustomConstructor => Constructor
 MutationObserver TODO CustomConstructor => Constructor

These following cases have been assigned:
 FontFaceSet 
 DocumentTimeline 
 Animation  
 IntersectionObserverEntry
 Document 
 DeviceMotionEvent  
 DeviceOrientationEvent
 Path2D

This has been filed:
 ResizeObserverEntry

I will start to tackle down these ones:
PerformanceObserver
VRLayer
CustomEvent 
ExtendableMessageEvent
USBOutTransferResult
USBIsochronousOutTransferResult
USBIsochronousOutTransferPacket
USBIsochronousInTransferResult
USBIsochronousInTransferPacket
USBInTransferResult

TODO: Document, IntersectionObserverEntry, ResizeOberverEntry

I was working on IntersectionOverserverEntry today and realized this is blocked on DOMRectInit replacing ClientRect. So I might have to wait to get this fixed. 

Seems like everything else is filed/handled/blocked at the moment. I guess there is no additional work for me to do at the moment? foolip@ WDYT? 

Since you've gone through the list there's nothing more to do here. If the set of missing constructors changed while you where working through the list or you missed something that's OK, they'll be noticed again sooner or later.

I think we want to keep the tracking bug open, but perhaps ExternalDependency best represents the current status?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4a0b36d59f90488e3296535e84e009729ee2c53f

commit 4a0b36d59f90488e3296535e84e009729ee2c53f
Author: foolip <foolip@chromium.org>
Date: Wed Apr 26 12:43:26 2017

Upstream FontFaceSetLoadEvent constructor test to wpt

Fixes https://github.com/w3c/web-platform-tests/issues/4822

BUG=673664
R=lunalu@chromium.org,kojii@chromium.org,ksakamoto@chromium.org

Review-Url: https://codereview.chromium.org/2841903002
Cr-Commit-Position: refs/heads/master@{#467306}

[modify] https://crrev.com/4a0b36d59f90488e3296535e84e009729ee2c53f/third_party/WebKit/LayoutTests/W3CImportExpectations
[add] https://crrev.com/4a0b36d59f90488e3296535e84e009729ee2c53f/third_party/WebKit/LayoutTests/external/wpt/css-font-loading/fontfacesetloadevent-constructor.html
[delete] https://crrev.com/c95e21cadda8ce43f68dc87d1c65d3ae39ab7850/third_party/WebKit/LayoutTests/fast/css/fontfacesetloadevent-constructor.html