Bug 1583203 - Annotate nsINode::OwnerDoc() as MOZ_NONNULL_RETURN. r=smaug

People keep adding useless null-checks and it was not clear what the consensus
was from bug 1441165, but this should be unobjectionable I guess.

Differential Revision: https://phabricator.services.mozilla.com/D46781

--HG--
extra : moz-landing-system : lando

docshell/base/nsDocShellTreeOwner.cpp

@@ -1305,10 +1305,8 @@ void ChromeTooltipListener::sTooltipCallback(nsITimer* aTimer,
                           self->mMouseScreenY - screenDot.y / scaleFactor,
                           tooltipText, directionText);
         self->mLastShownTooltipText = std::move(tooltipText);
-        if (self->mPossibleTooltipNode->OwnerDoc()) {
-          self->mLastDocshell = do_GetWeakReference(
-              self->mPossibleTooltipNode->OwnerDoc()->GetDocShell());
-        }
+        self->mLastDocshell = do_GetWeakReference(
+            self->mPossibleTooltipNode->OwnerDoc()->GetDocShell());
       }
     }
 

dom/base/nsINode.h

@@ -597,13 +597,15 @@ class nsINode : public mozilla::dom::EventTarget {
    *
    * For all other cases OwnerDoc and GetOwnerDocument behave identically.
    */
-  Document* OwnerDoc() const { return mNodeInfo->GetDocument(); }
+  Document* OwnerDoc() const MOZ_NONNULL_RETURN {
+    return mNodeInfo->GetDocument();
+  }
 
   /**
    * Return the "owner document" of this node as an nsINode*.  Implemented
    * in Document.h.
    */
-  inline nsINode* OwnerDocAsNode() const;
+  inline nsINode* OwnerDocAsNode() const MOZ_NONNULL_RETURN;
 
   /**
    * Returns true if the content has an ancestor that is a document.

dom/html/HTMLMediaElement.cpp

@@ -2175,7 +2175,7 @@ void HTMLMediaElement::Load() {
        HasAttr(kNameSpaceID_None, nsGkAtoms::autoplay),
        AutoplayPolicy::IsAllowedToPlay(*this), OwnerDoc(),
        DocumentOrigin(OwnerDoc()).get(),
-       OwnerDoc() ? OwnerDoc()->HasBeenUserGestureActivated() : 0, mMuted,
+       OwnerDoc()->HasBeenUserGestureActivated(), mMuted,
        mVolume));
 
   if (mIsRunningLoadMethod) {

dom/plugins/base/nsPluginInstanceOwner.cpp

@@ -3163,7 +3163,7 @@ void nsPluginInstanceOwner::SetFrame(nsPluginFrame* aFrame) {
 
   // If we already have a frame that is changing or going away...
   if (mPluginFrame) {
-    if (content && content->OwnerDoc() && content->OwnerDoc()->GetWindow()) {
+    if (content && content->OwnerDoc()->GetWindow()) {
       nsCOMPtr<EventTarget> windowRoot =
           content->OwnerDoc()->GetWindow()->GetTopWindowRoot();
       if (windowRoot) {

dom/xbl/nsXBLService.cpp

@@ -455,7 +455,7 @@ nsresult nsXBLService::LoadBindings(Element* aElement, nsIURI* aURL,
   // in AllowXULXBL() documents in content process in production without
   // knowing.
   if (XRE_IsContentProcess() &&
-      IsSystemOrChromeURLPrincipal(aOriginPrincipal) && aElement->OwnerDoc() &&
+      IsSystemOrChromeURLPrincipal(aOriginPrincipal) &&
       !aElement->OwnerDoc()->AllowXULXBL()) {
     MOZ_ASSERT(false, "Unexpected XBL binding used in the content process");
   }

layout/style/nsTransitionManager.cpp

@@ -77,8 +77,7 @@ void ElementPropertyTransition::UpdateStartValueFromReplacedTransition() {
                                       CSSPropFlags::CanAnimateOnCompositor),
              "The transition property should be able to be run on the "
              "compositor");
-  MOZ_ASSERT(mTarget && mTarget->mElement->OwnerDoc(),
-             "We should have a valid document at this moment");
+  MOZ_ASSERT(mTarget, "We should have a valid target at this moment");
 
   dom::DocumentTimeline* timeline = mTarget->mElement->OwnerDoc()->Timeline();
   ComputedTiming computedTiming = GetComputedTimingAt(