176505: Fix composer/mail compose regression, back out jag. a=blizzard & #mozilla

content/base/src/nsFrameLoader.cpp

@@ -450,9 +450,17 @@ nsFrameLoader::EnsureDocShell()
       }
     }
 
-    // if it isn't content, set it to the parent's type
-    PRInt32 shellType = isContent ? nsIDocShellTreeItem::typeContent : parentType;
-    docShellAsItem->SetItemType(shellType);
+    if (isContent) {
+      // The web shell's type is content.
+
+      docShellAsItem->SetItemType(nsIDocShellTreeItem::typeContent);
+    } else {
+      // Inherit our type from our parent webshell.  If it is
+      // chrome, we'll be chrome.  If it is content, we'll be
+      // content.
+
+      docShellAsItem->SetItemType(parentType);
+    }
 
     parentAsNode->AddChild(docShellAsItem);
 
@@ -461,8 +469,7 @@ nsFrameLoader::EnsureDocShell()
       parentAsItem->GetTreeOwner(getter_AddRefs(parentTreeOwner));
 
       if(parentTreeOwner) {
-        PRBool is_primary = shellType == nsIDocShellTreeItem::typeChrome &&
-                            value.Equals(NS_LITERAL_STRING("content-primary"));
+        PRBool is_primary = value.Equals(NS_LITERAL_STRING("content-primary"));
 
         parentTreeOwner->ContentShellAdded(docShellAsItem, is_primary,
                                            value.get());

layout/generic/nsFrameFrame.cpp

@@ -683,10 +683,7 @@ nsHTMLFrameOuterFrame::AttributeChanged(nsIPresContext* aPresContext,
       nsCOMPtr<nsIDocShellTreeOwner> parentTreeOwner;
       parentAsItem->GetTreeOwner(getter_AddRefs(parentTreeOwner));
       if (parentTreeOwner) {
-        PRInt32 shellType;
-        parentAsItem->GetItemType(&shellType);
         PRBool is_primary_content =
-          shellType == nsIDocShellTreeItem::typeChrome &&
           value.EqualsIgnoreCase("content-primary");
 
         parentTreeOwner->ContentShellAdded(docShellAsItem, is_primary_content,

layout/html/document/src/nsFrameFrame.cpp

@@ -683,10 +683,7 @@ nsHTMLFrameOuterFrame::AttributeChanged(nsIPresContext* aPresContext,
       nsCOMPtr<nsIDocShellTreeOwner> parentTreeOwner;
       parentAsItem->GetTreeOwner(getter_AddRefs(parentTreeOwner));
       if (parentTreeOwner) {
-        PRInt32 shellType;
-        parentAsItem->GetItemType(&shellType);
         PRBool is_primary_content =
-          shellType == nsIDocShellTreeItem::typeChrome &&
           value.EqualsIgnoreCase("content-primary");
 
         parentTreeOwner->ContentShellAdded(docShellAsItem, is_primary_content,