Bug 1829189 - Make OnAttrSetButNotChanged and AfterSetAttr infallible. r=smaug

Same rg + sed shenanigans as the first patch.

There were two that could fail, both due to OOM:

 * HTMLInputElement::AfterSetAttr: If we fail (only in the type=range
   case) we end up with an old value without it being clamped by
   min/max/step.

 * HTMLBodyElement::AfterSetAttr: If we fail we won't peek up the
   DocShell's frame margins and styling could be incorrect.

That seems better than having to deal with broken states after we've
already set the attribute.

Depends on D176069

Differential Revision: https://phabricator.services.mozilla.com/D176070

dom/html/HTMLMediaElement.cpp

@@ -4728,11 +4728,11 @@ bool HTMLMediaElement::IsHTMLFocusable(bool aWithMouse, bool* aIsFocusable,
 
 int32_t HTMLMediaElement::TabIndexDefault() { return 0; }
 
-nsresult HTMLMediaElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
-                                        const nsAttrValue* aValue,
-                                        const nsAttrValue* aOldValue,
-                                        nsIPrincipal* aMaybeScriptedPrincipal,
-                                        bool aNotify) {
+void HTMLMediaElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
+                                    const nsAttrValue* aValue,
+                                    const nsAttrValue* aOldValue,
+                                    nsIPrincipal* aMaybeScriptedPrincipal,
+                                    bool aNotify) {
   if (aNameSpaceID == kNameSpaceID_None) {
     if (aName == nsGkAtoms::src) {
       mSrcMediaSource = nullptr;
@@ -4785,9 +4785,10 @@ nsresult HTMLMediaElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
       aNameSpaceID, aName, aValue, aOldValue, aMaybeScriptedPrincipal, aNotify);
 }
 
-nsresult HTMLMediaElement::OnAttrSetButNotChanged(
-    int32_t aNamespaceID, nsAtom* aName, const nsAttrValueOrString& aValue,
-    bool aNotify) {
+void HTMLMediaElement::OnAttrSetButNotChanged(int32_t aNamespaceID,
+                                              nsAtom* aName,
+                                              const nsAttrValueOrString& aValue,
+                                              bool aNotify) {
   AfterMaybeChangeAttr(aNamespaceID, aName, aNotify);
 
   return nsGenericHTMLElement::OnAttrSetButNotChanged(aNamespaceID, aName,