Clicking a non-focusable element in an inactive frame should clear focus in the frame.

Source/core/page/FocusController.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nuanti Ltd.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 604 matching lines @@
 
     selection.clear();
 }
 
 bool FocusController::setFocusedElement(Element* element, PassRefPtr<Frame> newFocusedFrame, FocusDirection direction)
 {
     RefPtr<Frame> oldFocusedFrame = focusedFrame();
     RefPtr<Document> oldDocument = oldFocusedFrame ? oldFocusedFrame->document() : 0;
 
     Element* oldFocusedElement = oldDocument ? oldDocument->focusedElement() : 0;
-    if (oldFocusedElement == element)
+    if (element && oldFocusedElement == element)
         return true;
 
     // FIXME: Might want to disable this check for caretBrowsing
     if (oldFocusedElement && oldFocusedElement->isRootEditableElement() && !relinquishesEditingFocus(oldFocusedElement))
         return false;
 
     m_page->editorClient().willSetInputMethodState();
 
-    clearSelectionIfNeeded(oldFocusedFrame.get(), newFocusedFrame.get(), element);
-
-    if (!element) {
-        if (oldDocument)
-            oldDocument->setFocusedElement(0);
-        return true;
-    }
-
-    RefPtr<Document> newDocument(element->document());
+    RefPtr<Document> newDocument;
+    if (element)
+        newDocument = &element->document();
+    else if (newFocusedFrame)
+        newDocument = newFocusedFrame->document();
 
     if (newDocument && newDocument->focusedElement() == element)
         return true;
 
+    clearSelectionIfNeeded(oldFocusedFrame.get(), newFocusedFrame.get(), element);
+
     if (oldDocument && oldDocument != newDocument)
         oldDocument->setFocusedElement(0);
 
     if (newFocusedFrame && !newFocusedFrame->page()) {
         setFocusedFrame(0);
         return false;
     }
     setFocusedFrame(newFocusedFrame);
 
     // Setting the focused node can result in losing our last reft to node when JS event handlers fire.
@@ skipping 243 matching lines @@
         startingRect = nodeRectInAbsoluteCoordinates(container, true /* ignore border */);
         container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(direction, container);
         if (container && container->isDocumentNode())
             toDocument(container)->updateLayoutIgnorePendingStylesheets();
     } while (!consumed && container);
 
     return consumed;
 }
 
 } // namespace WebCore