--- a/dom/html/ImageDocument.cpp
+++ b/dom/html/ImageDocument.cpp
@@ -223,16 +223,22 @@ ImageDocument::StartDocumentLoad(const c
 #if defined(MOZ_WIDGET_ANDROID)
   mOriginalResolution = GetResolution();
 #endif
 
   NS_ASSERTION(aDocListener, "null aDocListener");
   *aDocListener = new ImageListener(this);
   NS_ADDREF(*aDocListener);
 
+#ifdef DEBUG
+    rv =
+#endif
+      CreateSyntheticDocument();
+  NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create synthetic document");
+
   return NS_OK;
 }
 
 void
 ImageDocument::Destroy()
 {
   if (mImageContent) {
     // Remove our event listener from the image content.
@@ -262,34 +268,31 @@ ImageDocument::SetScriptGlobalObject(nsI
   nsCOMPtr<EventTarget> target;
   if (mScriptGlobalObject &&
       aScriptGlobalObject != mScriptGlobalObject) {
     target = do_QueryInterface(mScriptGlobalObject);
     target->RemoveEventListener(NS_LITERAL_STRING("resize"), this, false);
     target->RemoveEventListener(NS_LITERAL_STRING("keypress"), this,
                                 false);
   }
+  if (mImageContent) {
+    target = do_QueryInterface(mImageContent);
+    target->RemoveEventListener(NS_LITERAL_STRING("load"), this, false);
+    target->RemoveEventListener(NS_LITERAL_STRING("click"), this, false);
+
+  }
 
   // Set the script global object on the superclass before doing
   // anything that might require it....
   MediaDocument::SetScriptGlobalObject(aScriptGlobalObject);
 
   if (aScriptGlobalObject) {
-    if (!GetRootElement()) {
-      // Create synthetic document
-#ifdef DEBUG
-      nsresult rv =
-#endif
-        CreateSyntheticDocument();
-      NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create synthetic document");
-
-      target = do_QueryInterface(mImageContent);
-      target->AddEventListener(NS_LITERAL_STRING("load"), this, false);
-      target->AddEventListener(NS_LITERAL_STRING("click"), this, false);
-    }
+    target = do_QueryInterface(mImageContent);
+    target->AddEventListener(NS_LITERAL_STRING("load"), this, false);
+    target->AddEventListener(NS_LITERAL_STRING("click"), this, false);
 
     target = do_QueryInterface(aScriptGlobalObject);
     target->AddEventListener(NS_LITERAL_STRING("resize"), this, false);
     target->AddEventListener(NS_LITERAL_STRING("keypress"), this, false);
 
     if (GetReadyStateEnum() != nsIDocument::READYSTATE_COMPLETE) {
       LinkStylesheet(NS_LITERAL_STRING("resource://content-accessible/ImageDocument.css"));
       if (!nsContentUtils::IsChildOfSameType(this)) {

--- a/dom/html/MediaDocument.cpp
+++ b/dom/html/MediaDocument.cpp
@@ -325,16 +325,19 @@ MediaDocument::LinkStylesheet(const nsAS
   NS_ENSURE_TRUE(link, NS_ERROR_OUT_OF_MEMORY);
 
   link->SetAttr(kNameSpaceID_None, nsGkAtoms::rel,
                 NS_LITERAL_STRING("stylesheet"), true);
 
   link->SetAttr(kNameSpaceID_None, nsGkAtoms::href, aStylesheet, true);
 
   Element* head = GetHeadElement();
+  if (!head) {
+    return NS_ERROR_FAILURE;
+  }
   return head->AppendChildTo(link, false);
 }
 
 nsresult
 MediaDocument::LinkScript(const nsAString& aScript)
 {
   RefPtr<mozilla::dom::NodeInfo> nodeInfo;
   nodeInfo = mNodeInfoManager->GetNodeInfo(nsGkAtoms::script, nullptr,
@@ -345,16 +348,19 @@ MediaDocument::LinkScript(const nsAStrin
   NS_ENSURE_TRUE(script, NS_ERROR_OUT_OF_MEMORY);
 
   script->SetAttr(kNameSpaceID_None, nsGkAtoms::type,
                   NS_LITERAL_STRING("text/javascript"), true);
 
   script->SetAttr(kNameSpaceID_None, nsGkAtoms::src, aScript, true);
 
   Element* head = GetHeadElement();
+  if (!head) {
+    return NS_ERROR_FAILURE;
+  }
   return head->AppendChildTo(script, false);
 }
 
 void
 MediaDocument::UpdateTitleAndCharset(const nsACString& aTypeStr,
                                      nsIChannel* aChannel,
                                      const char* const* aFormatNames,
                                      int32_t aWidth, int32_t aHeight,