RESOLVED FIXED 144499
Postpone caption style sheet creation 
https://bugs.webkit.org/show_bug.cgi?id=144499
Summary Postpone caption style sheet creation
Eric Carlson
Reported 2015-05-01 13:58:08 PDT
CaptionUserPreferences::updateCaptionStyleSheetOverride() is called when a <video> element is created. This is a fairly expensive operation and the style sheet it generates is only needed when the <video> has captions, so it should be postponed as long as possible.
Attachments
Proposed patch. (9.42 KB, patch)
2015-05-01 17:19 PDT, Eric Carlson 		no flags
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Eric Carlson
Comment 1 2015-05-01 13:58:34 PDT
rdar://problem/20691225
Eric Carlson
Comment 2 2015-05-01 17:19:51 PDT
Created attachment 252203 [details] Proposed patch.
Simon Fraser (smfr)
Comment 3 2015-05-01 17:32:56 PDT
Comment on attachment 252203 [details] Proposed patch. View in context: https://bugs.webkit.org/attachment.cgi?id=252203&action=review > Source/WebCore/html/HTMLMediaElement.cpp:480 > + if (m_haveRegisteredForCaptionPreferenceChanges) > + document.unregisterForCaptionPreferencesChangedCallbacks(this); Does this need to set m_haveRegisteredForCaptionPreferenceChanges=false? Or maybe my suggested rename would clarify. > Source/WebCore/html/HTMLMediaElement.h:888 > + bool m_haveRegisteredForCaptionPreferenceChanges { false }; Would this be better as m_hasHadTextTrack?
Eric Carlson
Comment 4 2015-05-01 17:41:28 PDT
Comment on attachment 252203 [details] Proposed patch. View in context: https://bugs.webkit.org/attachment.cgi?id=252203&action=review >> Source/WebCore/html/HTMLMediaElement.cpp:480 >> + document.unregisterForCaptionPreferencesChangedCallbacks(this); > > Does this need to set m_haveRegisteredForCaptionPreferenceChanges=false? Or maybe my suggested rename would clarify. No, because we want to re-register if the element is inserted back into the DOM (like the layout test does). I will rename it.
Simon Fraser (smfr)
Comment 5 2015-05-01 17:55:01 PDT
Comment on attachment 252203 [details] Proposed patch. View in context: https://bugs.webkit.org/attachment.cgi?id=252203&action=review > Source/WebCore/page/CaptionUserPreferencesMediaAF.cpp:200 > + // Generating and registering the caption stylesheet can be expensive and this method is called indirectly when the parser creates an audio or Maybe early return on if (m_listeningForPreferenceChanges) before this whole block.
Eric Carlson
Comment 6 2015-05-01 18:16:01 PDT
Committed r183705: https://trac.webkit.org/r183705
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