Bug 239770 – [ macOS Debug wk2 ] Thirteen imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/ are a flaky crash (ASSERTION FAILED: willBeComposited == needsToBeComposited(layer, queryData))

• Component: Media
• Status: RESOLVED FIXED

[Karl Rackler]

Description:
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_order_canplay_canplaythrough.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_order_loadedmetadata_loadeddata.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/readyState_during_canplaythrough.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/readyState_during_playing.html

The first failure that I saw on the dashboard was 4/4/2022 at r292293, but this does not appear relevant to causing this issue.


REPRODUCTION STEPS
I can reproduce this on r292959, but unable to reproduce it on 292262.  

Command: 
run-webkit-tests --root --exit-after-n-failures 1 --exit-after-n-crashes-or-timeouts 1 --iterations 50 -f --no-retry

Result: 
Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_order_canplay_canplaythrough.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_order_loadedmetadata_loadeddata.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/readyState_during_canplaythrough.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/readyState_during_playing.html [ Crash ]


History:
https://results.webkit.org/?suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_order_canplay_canplaythrough.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_order_loadedmetadata_loadeddata.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FreadyState_during_canplaythrough.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FreadyState_during_playing.html&platform=mac&style=debug&limit=50000&flavor=gpuprocess&flavor=wk2

Crash Log:
No crash log found for com.apple.WebKit.WebContent.Development:86372.

[Radar WebKit Bug Importer]

<rdar://problem/92334616>

[Karl Rackler]

Created attachment 458362 [details]
event_order_canplay_canplaythrough-crash-log

[Karl Rackler]

Created attachment 458363 [details]
event_order_canplay_canplaythrough-stderr

[Karl Rackler]

Created attachment 458364 [details]
event_order_loadedmetadata_loadeddata-crash-log

[Karl Rackler]

Created attachment 458365 [details]
event_order_loadedmetadata_loadeddata-stderr

[Karl Rackler]

Created attachment 458366 [details]
readyState_during_canplaythrough-crash-log

[Karl Rackler]

Created attachment 458367 [details]
readyState_during_canplaythrough-stderr

[Karl Rackler]

Created attachment 458368 [details]
readyState_during_playing-crash-log

[Karl Rackler]

Created attachment 458369 [details]
readyState_during_playing-stderr

[Karl Rackler]

I have marked these tests as a flaky crash while this issue is investigated.

[Alexey Proskuryakov]

com.apple.WebKit.Networking.Development: Could not compile WebContent sandbox: /Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.NetworkProcess.sb:549:13: unbound variable:
	MSC_mach_msg2_trap

[Karl Rackler]

Landed https://commits.webkit.org/249989@main (r293429)!

[Karl Rackler]

Reopened because the issue is still being investigated.

[Karl Rackler]

Reopened because the issue is still being investigated.

[Karl Rackler]

Description: Adding two additional tests
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_pause.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_play.html

REPRODUCTION STEPS
I can reproduce this on r292959, but unable to reproduce it on 292262.  
The regression is between r292262-r295959.

Command: 
run-webkit-tests --root --exit-after-n-failures 1 --exit-after-n-crashes-or-timeouts 1 --iterations 50 -f --no-retry

Result: 
Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_pause.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_play.html [ Crash ]

History:
https://results.webkit.org/?suite=layout-tests&suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_pause.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_play.html&platform=mac&flavor=wk2&style=debug&limit=50000

Crash Log:
No crash log found for com.apple.WebKit.Networking.Development:26056.

stderr: 
com.apple.WebKit.Networking.Development: Could not compile WebContent sandbox: /Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.NetworkProcess.sb:549:13: unbound variable:
	MSC_mach_msg2_trap


I have marked this test as a flaky crash while this issue is investigated.

[Karl Rackler]

Created attachment 458381 [details]
event_pause-crash-log

[Karl Rackler]

Created attachment 458382 [details]
event_pause-stderr

[Karl Rackler]

Created attachment 458383 [details]
event_play-crash-log

[Karl Rackler]

Created attachment 458384 [details]
event_play-stderr

[Karl Rackler]

Pull request: https://github.com/WebKit/WebKit/pull/393

[EWS]

Test gardening commit r293437 (249995@main): <https://commits.webkit.org/249995@main>

Reviewed commits have been landed. Closing PR #393 and removing active labels.

[Per Arne Vollan]

I believe the sandbox issue was fixed in https://trac.webkit.org/changeset/292975/webkit.

[Alexey Proskuryakov]

Got it. Seeing this for recent crashes:

ASSERTION FAILED: willBeComposited == needsToBeComposited(layer, queryData)
./rendering/RenderLayerCompositor.cpp(1184) : void WebCore::RenderLayerCompositor::computeCompositingRequirements(WebCore::RenderLayer *, WebCore::RenderLayer &, WebCore::LayerOverlapMap &, WebCore::RenderLayerCompositor::CompositingState &, WebCore::RenderLayerCompositor::BackingSharingState &, bool &)
1   0x1f569e8f9 WTFCrash
2   0x1ce777c2b WTFCrashWithInfo(int, char const*, char const*, int)
3   0x1d3cc37e5 WebCore::RenderLayerCompositor::computeCompositingRequirements(WebCore::RenderLayer*, WebCore::RenderLayer&, WebCore::LayerOverlapMap&, WebCore::RenderLayerCompositor::CompositingState&, WebCore::RenderLayerCompositor::BackingSharingState&, bool&)
4   0x1d3cc33f0 WebCore::RenderLayerCompositor::computeCompositingRequirements(WebCore::RenderLayer*, WebCore::RenderLayer&, WebCore::LayerOverlapMap&, WebCore::RenderLayerCompositor::CompositingState&, WebCore::RenderLayerCompositor::BackingSharingState&, bool&)

[Simon Fraser (smfr)]

This happens when media compositing state happens without correctly informing RenderLayerCompositor.

[Karl Rackler]

Description: Adding seven additional tests
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_canplay.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_loadeddata.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_loadstart.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_timeupdate.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/networkState_during_progress.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/readyState_during_canplay.html
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/readyState_during_loadeddata.html

REPRODUCTION STEPS
I can reproduce this on r292959, but unable to reproduce it on 292262.  
The regression is between r292262-r295959.

Command: 
run-webkit-tests --root --exit-after-n-failures 1 --exit-after-n-crashes-or-timeouts 1 --iterations 50 -f --no-retry

Result: 
Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_canplay.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_loadeddata.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_loadstart.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_timeupdate.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/networkState_during_progress.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/readyState_during_canplay.html [ Crash ]

Regressions: Unexpected crashes (1)
  imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/readyState_during_loadeddata.html [ Crash ]

History:
https://results.webkit.org/?suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_canplay.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_loadeddata.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_loadstart.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_timeupdate.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FnetworkState_during_progress.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FreadyState_during_canplay.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FreadyState_during_loadeddata.html&limit=50000&platform=mac&flavor=wk2&style=debug

Crash Log:
No crash log found for com.apple.WebKit.Networking.Development:26056.

stderr: 
com.apple.WebKit.Networking.Development: Could not compile WebContent sandbox: /Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.NetworkProcess.sb:549:13: unbound variable:
	MSC_mach_msg2_trap


I have marked this test as a flaky crash while this issue is investigated.

[Karl Rackler]

Created attachment 458393 [details]
event_canplay-crash-log

[Karl Rackler]

Created attachment 458394 [details]
event_canplay-stderr

[Karl Rackler]

Created attachment 458395 [details]
event_loadeddata-crash-log

[Karl Rackler]

Created attachment 458396 [details]
event_loadeddata-stderr

[Karl Rackler]

Created attachment 458397 [details]
event_loadstart-crash-log

[Karl Rackler]

Created attachment 458398 [details]
event_loadstart-stderr

[Karl Rackler]

Created attachment 458399 [details]
event_timeupdate-crash-log

[Karl Rackler]

Created attachment 458400 [details]
event_timeupdate-stderr

[Karl Rackler]

Created attachment 458401 [details]
networkState_during_progress-crash-log

[Karl Rackler]

Created attachment 458402 [details]
readyState_during_canplay-stderr

[Karl Rackler]

Created attachment 458403 [details]
readyState_during_loadeddata-crash-log

[Karl Rackler]

Created attachment 458404 [details]
readyState_during_loadeddata-stderr

[Simon Fraser (smfr)]

No need for all the duplicate logs.

com.apple.WebKit.Networking.Development: Could not compile WebContent sandbox: /Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.NetworkProcess.sb:549:13: unbound variable:
	MSC_mach_msg2_trap

sandbox initialization failed: /Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.NetworkProcess.sb:549:13: unbound variable:
	MSC_mach_msg2_trap

com.apple.WebKit.Networking.Development: Could not initialize sandbox profile [/Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.NetworkProcess.sb], error '/Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.NetworkProcess.sb:549:13: unbound variable:
	MSC_mach_msg2_trap
'
ENABLE_SANDBOX_MESSAGE_FILTER=YES
_OS_VERSION=12.3
WEBKIT2_FRAMEWORK_DIR=/Volumes/Builds/292959
DARWIN_USER_TEMP_DIR=/private/var/folders/t8/wt_bzchd67ddzrvh2ptzb39w0000gn/T/WebKitTestRunners-287mv_8z
DARWIN_USER_CACHE_DIR=/private/var/folders/t8/wt_bzchd67ddzrvh2ptzb39w0000gn/C/WebKitTestRunners-287mv_8z
HOME_DIR=/Users/karlrackler
HOME_LIBRARY_DIR=/Users/karlrackler/Library
HOME_LIBRARY_PREFERENCES_DIR=/Users/karlrackler/Library/Preferences
CPU=x86_64
com.apple.WebKit.Networking.Development: Unable to apply sandbox
1   0x113003759 WTFCrash
2   0x1490c7a0c WebKit::AuxiliaryProcess::initializeSandbox(WebKit::AuxiliaryProcessInitializationParameters const&, WebKit::SandboxInitializationParameters&)
3   0x148d072bc WebKit::NetworkProcess::initializeSandbox(WebKit::AuxiliaryProcessInitializationParameters const&, WebKit::SandboxInitializationParameters&)
4   0x1498260cd WebKit::AuxiliaryProcess::initialize(WebKit::AuxiliaryProcessInitializationParameters const&)
5   0x1491adf9e WebKit::NetworkProcess::NetworkProcess(WebKit::AuxiliaryProcessInitializationParameters&&)
6   0x1491ae40d WebKit::NetworkProcess::NetworkProcess(WebKit::AuxiliaryProcessInitializationParameters&&)

[Karl Rackler]

Pull request: https://github.com/WebKit/WebKit/pull/398

[Karl Rackler]

(In reply to Simon Fraser (smfr) from comment #38)
> No need for all the duplicate logs.
> 
> com.apple.WebKit.Networking.Development: Could not compile WebContent
> sandbox:
> /Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.
> NetworkProcess.sb:549:13: unbound variable:
> 	MSC_mach_msg2_trap
> 
> sandbox initialization failed:
> /Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.
> NetworkProcess.sb:549:13: unbound variable:
> 	MSC_mach_msg2_trap
> 
> com.apple.WebKit.Networking.Development: Could not initialize sandbox
> profile
> [/Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.
> NetworkProcess.sb], error
> '/Volumes/Builds/292959/WebKit.framework/Resources/com.apple.WebKit.
> NetworkProcess.sb:549:13: unbound variable:
> 	MSC_mach_msg2_trap
> '
> ENABLE_SANDBOX_MESSAGE_FILTER=YES
> _OS_VERSION=12.3
> WEBKIT2_FRAMEWORK_DIR=/Volumes/Builds/292959
> DARWIN_USER_TEMP_DIR=/private/var/folders/t8/wt_bzchd67ddzrvh2ptzb39w0000gn/
> T/WebKitTestRunners-287mv_8z
> DARWIN_USER_CACHE_DIR=/private/var/folders/t8/wt_bzchd67ddzrvh2ptzb39w0000gn/
> C/WebKitTestRunners-287mv_8z
> HOME_DIR=/Users/karlrackler
> HOME_LIBRARY_DIR=/Users/karlrackler/Library
> HOME_LIBRARY_PREFERENCES_DIR=/Users/karlrackler/Library/Preferences
> CPU=x86_64
> com.apple.WebKit.Networking.Development: Unable to apply sandbox
> 1   0x113003759 WTFCrash
> 2   0x1490c7a0c
> WebKit::AuxiliaryProcess::initializeSandbox(WebKit::
> AuxiliaryProcessInitializationParameters const&,
> WebKit::SandboxInitializationParameters&)
> 3   0x148d072bc
> WebKit::NetworkProcess::initializeSandbox(WebKit::
> AuxiliaryProcessInitializationParameters const&,
> WebKit::SandboxInitializationParameters&)
> 4   0x1498260cd
> WebKit::AuxiliaryProcess::initialize(WebKit::
> AuxiliaryProcessInitializationParameters const&)
> 5   0x1491adf9e
> WebKit::NetworkProcess::NetworkProcess(WebKit::
> AuxiliaryProcessInitializationParameters&&)
> 6   0x1491ae40d
> WebKit::NetworkProcess::NetworkProcess(WebKit::
> AuxiliaryProcessInitializationParameters&&)

Roger that.

[EWS]

Test gardening commit r293451 (250005@main): <https://commits.webkit.org/250005@main>

Reviewed commits have been landed. Closing PR #398 and removing active labels.

[Simon Fraser (smfr)]

I'd prefer we didn't garden around a sandbox crash.

[Simon Fraser (smfr)]

Sandbox crash was supposedly fixed in r292975. The current crashes all seem to be the compositing assertion.

[Simon Fraser (smfr)]

Repro:
imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_canplay_noautoplay.html imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/event_canplaythrough.html --iterations=100 --exit-after-n-failures=1 --expect-pass

[Simon Fraser (smfr)]

Debugging so far:
* RenderLayer::contentChanged() is called for the video element's layer, setting the NeedsPostLayoutCompositingUpdate bit
* some compositing update runs, does not make the video composited, clears the bit
* a later compositing update skips the the `willBeComposited = needsToBeComposited(layer, queryData);` line in RenderLayerCompositor::computeCompositingRequirements(), but the video should have become composited.

[Simon Fraser (smfr)]

Here's the problem:

18:19:55.658 71596 worker/0   RenderLayer 0x3ae195410 contentChanged 5
18:19:55.658 71596 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 0
...
18:19:55.659 71596 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 0
18:19:55.659 71596 worker/0   Clearing compositing requirements bits on layer RenderLayer 0x3ae195410 300x150
18:19:55.659 71596 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 1
18:19:55.659 71596 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 1
18:19:55.659 71596 worker/0   1 Mismatched compositing state on layer RenderLayer 0x3ae195410 300x150 willBeComposited 0 needsToBeComposited 1 did check 0
18:19:55.659 71596 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 1

So "canAccelerateVideoRendering" changes from 0 to 1 without a call to contentChanged(). That's on media code to get right.

[Simon Fraser (smfr)]

18:25:29.728 72341 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 0
18:25:29.728 72341 worker/0   Clearing compositing requirements bits on layer RenderLayer 0x45bf438e0 300x150
18:25:29.728 72341 worker/0   MediaPlayerPrivateAVFoundation 0x10f0a0d80 acceleratedRenderingStateChanged()
18:25:29.728 72341 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 1
18:25:29.728 72341 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 1
18:25:29.728 72341 worker/0   1 Mismatched compositing state on layer RenderLayer 0x45bf438e0 300x150 willBeComposited 0 needsToBeComposited 1 did check 0
18:25:29.728 72341 worker/0   requiresImmediateCompositing 0 shouldDisplayVideo 1 canAccelerateVideoRendering 1
18:25:29.728 72341 worker/0   ASSERTION FAILED: willBeComposited == needsToBeComposited(layer, queryData)

So MediaPlayerPrivateAVFoundation::acceleratedRenderingStateChanged() ran but did not trigger a call to contentChanged

[Simon Fraser (smfr)]

The contract here is that if the answer to HTMLMediaElemenet::supportsAcceleratedRendering() changes, then contentChanged(VideoChanged) has to be called. That's not happening reliably.

[Simon Fraser (smfr)]

Created attachment 458488 [details]
Patch

[Alexey Proskuryakov]

Comment on attachment 458488 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=458488&action=review

> Source/WebKit/ChangeLog:3
> +        [ macOS Debug wk2 ] Thirteen imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/ are a flaky crash (ASSERTION FAILED: willBeComposited == needsToBeComposited(layer, queryData))

Could you please unskip the tests?

[Simon Fraser (smfr)]

Created attachment 458528 [details]
Patch

[Simon Fraser (smfr)]

Created attachment 458529 [details]
Patch

[EWS]

Committed r293589 (250098@main): <https://commits.webkit.org/250098@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 458529 [details].

[Karl Rackler]

Verified tests no longer crashing.

History: 
https://results.webkit.org/?platform=mac&flavor=wk2&style=debug&limit=50000&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_canplay.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_loadeddata.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_loadstart.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_order_canplay_canplaythrough.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_order_loadedmetadata_loadeddata.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_pause.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_play.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2Fevent_timeupdate.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FnetworkState_during_progress.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FreadyState_during_canplay.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FreadyState_during_canplaythrough.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FreadyState_during_loadeddata.html&test=imported%2Fw3c%2Fweb-platform-tests%2Fhtml%2Fsemantics%2Fembedded-content%2Fmedia-elements%2FreadyState_during_playing.html