Oilpan: reliably track listening PlatformEventControllers.

Source/core/frame/PlatformEventDispatcher.h

Index: Source/core/frame/PlatformEventDispatcher.h
diff --git a/Source/core/frame/PlatformEventDispatcher.h b/Source/core/frame/PlatformEventDispatcher.h
index 406cf680ce7854cba0fbdfae4347f7baf5ba17a8..d05ddc9fc5a8f342fba0326b303bcf1f017cac69 100644
--- a/Source/core/frame/PlatformEventDispatcher.h
+++ b/Source/core/frame/PlatformEventDispatcher.h
@@ -5,6 +5,7 @@
 #ifndef PlatformEventDispatcher_h
 #define PlatformEventDispatcher_h
 
+#include "platform/heap/Handle.h"
 #include "wtf/Vector.h"
 
 namespace blink {
@@ -27,7 +28,7 @@ protected:
 private:
     void purgeControllers();
 
-    Vector<PlatformEventController*> m_controllers;
+    WillBePersistentHeapVector<RawPtrWillBeMember<PlatformEventController> > m_controllers;

[haraken, 2014/09/30 12:02:14]

Are you sure that this persistent heap vector of members doesn't cause a memory
leak? I'm wondering this since you're changing a raw pointer to a persistent
handle.

(Previously I tried to move PlatformEventDispatcher to the heap at the same time
and make m_controllers a HeapHashMap of weak members, although I didn't complete
the CL at that time :-)

[sof, 2014/09/30 12:12:21]

I haven't done a complete testrun with --enable-leak-detection, but the
module-specific tests that are relevant here don't show up leaks afaict.

That's for leaks on shutdown. If this unnecessarily prolong lifetimes, is a
separate matter. But the onus on unregistering ought to be with the controllers.

     bool m_needsPurge;
     bool m_isDispatching;
 };