gistfile.patch

diff --git a/devtools/client/framework/toolbox.js b/devtools/client/framework/toolbox.js
index c42d5ab..e40ffd7 100644
--- a/devtools/client/framework/toolbox.js
+++ b/devtools/client/framework/toolbox.js
@@ -1388,6 +1388,7 @@ Toolbox.prototype = {
     iframe.id = "toolbox-panel-iframe-" + id;
     iframe.setAttribute("flex", 1);
     iframe.setAttribute("forceOwnRefreshDriver", "");
+    iframe.setAttribute("useContentEventHandling", "true");
     iframe.tooltip = "aHTMLTooltip";
     iframe.style.visibility = "hidden";
 
diff --git a/dom/base/nsFrameLoader.cpp b/dom/base/nsFrameLoader.cpp
index d6b44b8..f5b1c76 100644
--- a/dom/base/nsFrameLoader.cpp
+++ b/dom/base/nsFrameLoader.cpp
@@ -2304,7 +2304,9 @@ nsFrameLoader::MaybeCreateDocShell()
   // in the nearest enclosing chrome shell.
   nsCOMPtr<nsIDOMEventTarget> chromeEventHandler;
 
-  if (parentType == nsIDocShellTreeItem::typeChrome) {
+  if (parentType == nsIDocShellTreeItem::typeChrome &&
+      !mOwnerContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::useContentEventHandling,
+                                  nsGkAtoms::_true, eCaseMatters)) {
     // Our parent shell is a chrome shell. It is therefore our nearest
     // enclosing chrome shell.
 
diff --git a/dom/base/nsGkAtomList.h b/dom/base/nsGkAtomList.h
index 10bb68e..e50e5a1 100644
--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -1289,6 +1289,7 @@ GK_ATOM(upperFirst, "upper-first")
 GK_ATOM(uri, "uri")
 GK_ATOM(use, "use")
 GK_ATOM(useAttributeSets, "use-attribute-sets")
+GK_ATOM(useContentEventHandling, "useContentEventHandling")
 GK_ATOM(usemap, "usemap")
 GK_ATOM(user_scalable, "user-scalable")
 GK_ATOM(userInput, "userInput")