Bug 1377752 - part2: Selection::NotifySelectionListeners() should make nsFocusManager not scroll new focused element into the view if it's not focused document r=smaug

When changing selection into a contenteditable element in non-focused document, new focused editor shouldn't be scrolled into the view for compatibility with the other browsers.

MozReview-Commit-ID: FabqizyJrPW

--HG--
extra : rebase_source : 5bd2a017ec4c4f4fc0a6f7644fba2769b3ffca2c

dom/base/Selection.cpp

@@ -3734,8 +3734,13 @@ Selection::NotifySelectionListeners()
         nsCOMPtr<nsIDOMElement> domElementToFocus =
           do_QueryInterface(newEditingHost->AsDOMNode());
         // Note that don't steal focus from focused window if the window doesn't
-        // have focus.
-        fm->SetFocus(domElementToFocus, nsIFocusManager::FLAG_NOSWITCHFRAME);
+        // have focus and if the window isn't focused window, shouldn't be
+        // scrolled to the new focused element.
+        uint32_t flags = nsIFocusManager::FLAG_NOSWITCHFRAME;
+        if (focusedWindow != fm->GetFocusedWindow()) {
+          flags |= nsIFocusManager::FLAG_NOSCROLL;
+        }
+        fm->SetFocus(domElementToFocus, flags);
       }
     }
   }