Bug 1490791 - Make ShadowRoot stylesheet list work only when the shad…

…ow root is connected. r=smaug

This avoids the issue of triggering stylesheet loads for disconnected stuff and
such, and is more consistent with Chrome and WebKit.

This is per the recent CSSWG resolution at
w3c/csswg-drafts#3096.

Differential Revision: https://phabricator.services.mozilla.com/D5699

UltraBlame original commit: 71f86120ca35d113a2462b2ffe68bc5accc813e4

dom/base/nsStyleLinkElement.cpp

@@ -1321,21 +1321,7 @@ doc
 thisContent
 -
 >
-IsInShadowTree
-(
-)
-?
-thisContent
--
->
-OwnerDoc
-(
-)
-:
-thisContent
--
->
-GetUncomposedDoc
+GetComposedDoc
 (
 )
 ;

testing/web-platform/tests/shadow-dom/ShadowRoot-interface.html

@@ -1224,33 +1224,6 @@
 }
 )
 ;
-assert_equals
-(
-shadowRoot
-.
-styleSheets
-.
-length
-0
-'
-shadowRoot
-.
-styleSheets
-must
-be
-empty
-when
-the
-shadow
-root
-does
-not
-contain
-any
-stylesheets
-'
-)
-;
 shadowRoot
 .
 innerHTML
@@ -1296,6 +1269,40 @@
 styleSheets
 .
 length
+0
+'
+shadowRoot
+.
+styleSheets
+must
+be
+empty
+when
+the
+shadow
+root
+is
+not
+connected
+'
+)
+;
+document
+.
+body
+.
+appendChild
+(
+host
+)
+;
+assert_equals
+(
+shadowRoot
+.
+styleSheets
+.
+length
 2
 '
 shadowRoot

testing/web-platform/tests/shadow-dom/untriaged/styles/test-003.html

@@ -410,46 +410,6 @@
 '
 )
 ;
-/
-/
-TODO
-Now
-this
-tests
-produces
-an
-error
-on
-Chromium
-because
-styleSheets
-.
-length
-/
-/
-returns
-0
-when
-the
-shadow
-root
-is
-orphaned
-.
-/
-/
-Tracking
-bug
-:
-http
-:
-/
-/
-crbug
-.
-com
-/
-392771
 test
 (
 unit
@@ -536,27 +496,6 @@
 style
 )
 ;
-/
-/
-The
-following
-line
-fixes
-the
-issue
-on
-Chromium
-http
-:
-/
-/
-crbug
-.
-com
-/
-392771
-/
-/
 d
 .
 body