Bug 803125 - Notify status tracker when image request is destroyed. r=joe

image/src/imgRequest.cpp

@@ -108,6 +108,9 @@ imgRequest::imgRequest(imgLoader* aLoader)
 
 imgRequest::~imgRequest()
 {
+  // The status tracker can outlive this request, and needs to know it's dying.
+  GetStatusTracker().ClearRequest();
+
   if (mURI) {
     nsAutoCString spec;
     mURI->GetSpec(spec);

image/src/imgStatusTracker.cpp

@@ -766,3 +766,9 @@ imgStatusTracker::MaybeUnblockOnload()
     SendUnblockOnload(iter.GetNext());
   }
 }
+
+void
+imgStatusTracker::ClearRequest()
+{
+  mRequest = nullptr;
+}

image/src/imgStatusTracker.h

@@ -186,6 +186,9 @@ public:
 
   void MaybeUnblockOnload();
 
+  // Null out any reference to an associated image request
+  void ClearRequest();
+
   // Weak pointer getters - no AddRefs.
   inline mozilla::image::Image* GetImage() const { return mImage; };
   inline imgRequest* GetRequest() const { return mRequest; };