Prefer content property to img src on image elements.
Given the compat reports in bug 1484928, I don't think it's worth
keeping the current behavior.
Our behavior should match other browsers now. Rather than making
content: url() work everywhere even for otherwise-replaced elements,
just special-case this since that's what other browsers seem to do.
Differential Revision: https://phabricator.services.mozilla.com/D131797
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1742411
gecko-commit: f9582e5a1d29a628343593f3fb3377db8fda32d5
gecko-reviewers: dholbert
diff --git a/css/css-content/element-replacement-image-no-src-ref.html b/css/css-content/element-replacement-image-no-src-ref.html
new file mode 100644
index 0000000..b9ba2e9
--- /dev/null
+++ b/css/css-content/element-replacement-image-no-src-ref.html
@@ -0,0 +1,2 @@
+<!doctype html>
+<img src="/images/yellow.png" width=100 height=100>
diff --git a/css/css-content/element-replacement-image-no-src.tentative.html b/css/css-content/element-replacement-image-no-src.tentative.html
new file mode 100644
index 0000000..0c400ed
--- /dev/null
+++ b/css/css-content/element-replacement-image-no-src.tentative.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<title>content: url() works on image</title>
+<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
+<link rel="help" href="https://drafts.csswg.org/css-content-3/#content-property">
+<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/2831">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1484928">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1742411">
+<link rel="match" href="element-replacement-image-no-src-ref.html">
+<img style="content: url(/images/yellow.png)" width=100 height=100>
diff --git a/css/css-content/element-replacement-image-src.tentative.html b/css/css-content/element-replacement-image-src.tentative.html
new file mode 100644
index 0000000..33547e2
--- /dev/null
+++ b/css/css-content/element-replacement-image-src.tentative.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<title>content: url() works on image</title>
+<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
+<link rel="help" href="https://drafts.csswg.org/css-content-3/#content-property">
+<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/2831">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1484928">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1742411">
+<link rel="match" href="element-replacement-image-no-src-ref.html">
+<img src="/images/blue.png" style="content: url(/images/yellow.png)" width=100 height=100>
