In order to tailor certain security checks to the caller that is
attempting to load a particular piece of content, we need to be able to
attach an appropriate triggering principal to the corresponding requests.
Since most HTML content is loaded based on attribute values, this means
capturing the subject principal of the caller who sets those attributes,
which in turn means we need to make it available to `AfterSetAttr` hooks
on all relevant element types.
Since these are just interpreted comments, there's 0 impact on actual code.
This removes all lines that match /* vim: set(.*)tw=80: */ with S&R -- there are
a few others scattered around which will be removed manually in a second part.
* Rename nsIDOMEventTarget::PreHandleEvent to nsIDOMEventTarget::GetEventTargetParent
* Add nsIDOMEventTarget::PreHandleEvent
* Add EventTargetChainItem::GetFirstEventTarget
* Call EventTargetChainItem::PreHandleEvent even it sets mCanHandle=false
* Move form control frame focus/blur from nsGenericHTMLFormElement::GetEventTargetParent to PreHandleEvent
* Move fire change event from HTMLTextAreaElement::GetEventTargetParent to PreHandleEvent
* Refine nsXULElement::GetEventTargetParent
* Move dispatch XUL command from nsXULElement::GetEventTargetParent to PreHandleEvent
* Move fire events and set value from HTMLInputElement::GetEventTargetParent to PreHandleEvent
* Add test case
* Let HTMLInputElement delegate event handling to it's parent class
* Refine EventTargetChain flags to reduce overheads
* Refine event target chain creation
* Refine assertion in EventTargetChainItem::Create
Tag #1375