Web Inspector: NMI add instrumentation to widely used ActiveDOMObjects. XMLHttpRequest, Prerenderer, HTMLMediaElement and DOMTimer.
https://bugs.webkit.org/show_bug.cgi?id=102818

Reviewed by Vsevolod Vlasov.

Our test bot counts pointers which don't match with objects allocated by tcmalloc.
This counter becomes nonzero after instrumenting ActiveDOMObject class.
It happens because it is the base class for many other classes (~30).
And almost all these classes use multiple inheritance.

* dom/Document.cpp:
(WebCore::Document::reportMemoryUsage):
* dom/DocumentEventQueue.cpp:
* html/HTMLMediaElement.cpp:
(WebCore::HTMLMediaElement::reportMemoryUsage):
(WebCore):
* html/HTMLMediaElement.h:
* loader/Prerenderer.cpp:
(WebCore::Prerenderer::reportMemoryUsage):
(WebCore):
* loader/Prerenderer.h:
(Prerenderer):
* page/DOMTimer.cpp:
(WebCore::DOMTimer::reportMemoryUsage):
(WebCore):
* page/DOMTimer.h:
(DOMTimer):
* xml/XMLHttpRequest.cpp:
(WebCore::XMLHttpRequest::reportMemoryUsage):
(WebCore):
* xml/XMLHttpRequest.h:
(XMLHttpRequest):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@135384 268f45cc-cd09-0410-ab3c-d52691b4dbfc