diff -r 000000000000 -r 6474c204b198 layout/style/ImageLoader.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/style/ImageLoader.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,120 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// A class that handles style system image loads (other image loads are handled
+// by the nodes in the content tree).
+
+#ifndef mozilla_css_ImageLoader_h___
+#define mozilla_css_ImageLoader_h___
+
+#include "nsClassHashtable.h"
+#include "nsHashKeys.h"
+#include "nsCSSValue.h"
+#include "imgIRequest.h"
+#include "imgIOnloadBlocker.h"
+#include "imgINotificationObserver.h"
+#include "mozilla/Attributes.h"
+
+class nsIFrame;
+class nsIDocument;
+class nsPresContext;
+class nsIURI;
+class nsIPrincipal;
+
+namespace mozilla {
+namespace css {
+
+class ImageLoader MOZ_FINAL : public imgINotificationObserver,
+                              public imgIOnloadBlocker {
+public:
+  typedef mozilla::css::ImageValue Image;
+
+  ImageLoader(nsIDocument* aDocument)
+  : mDocument(aDocument),
+    mInClone(false)
+  {
+    MOZ_ASSERT(mDocument);
+  }
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_IMGIONLOADBLOCKER
+  NS_DECL_IMGINOTIFICATIONOBSERVER
+
+  void DropDocumentReference();
+
+  void MaybeRegisterCSSImage(Image* aImage);
+  void DeregisterCSSImage(Image* aImage);
+
+  void AssociateRequestToFrame(imgIRequest* aRequest,
+                               nsIFrame* aFrame);
+
+  void DisassociateRequestFromFrame(imgIRequest* aRequest,
+                                    nsIFrame* aFrame);
+
+  void DropRequestsForFrame(nsIFrame* aFrame);
+
+  void SetAnimationMode(uint16_t aMode);
+
+  void ClearFrames();
+
+  void LoadImage(nsIURI* aURI, nsIPrincipal* aPrincipal, nsIURI* aReferrer,
+                 Image* aCSSValue);
+
+  void DestroyRequest(imgIRequest* aRequest);
+
+private:
+  // We need to be able to look up the frames associated with a request (for
+  // delivering notifications) and the requests associated with a frame (when
+  // the frame goes away). Thus we maintain hashtables going both ways.  These
+  // should always be in sync.
+
+  typedef nsTArray<nsIFrame*> FrameSet;
+  typedef nsTArray<nsCOMPtr<imgIRequest> > RequestSet;
+  typedef nsTHashtable<nsPtrHashKey<Image> > ImageHashSet;
+  typedef nsClassHashtable<nsISupportsHashKey,
+                           FrameSet> RequestToFrameMap;
+  typedef nsClassHashtable<nsPtrHashKey<nsIFrame>,
+                           RequestSet> FrameToRequestMap;
+
+  void AddImage(Image* aCSSImage);
+  void RemoveImage(Image* aCSSImage);
+
+  nsPresContext* GetPresContext();
+
+  void DoRedraw(FrameSet* aFrameSet);
+
+  static PLDHashOperator
+  SetAnimationModeEnumerator(nsISupports* aKey, FrameSet* aValue,
+                             void* aClosure);
+
+  nsresult OnStartContainer(imgIRequest *aRequest, imgIContainer* aImage);
+  nsresult OnStopFrame(imgIRequest *aRequest);
+  nsresult OnImageIsAnimated(imgIRequest *aRequest);
+  nsresult FrameChanged(imgIRequest* aRequest);
+  // Do not override OnDataAvailable since background images are not
+  // displayed incrementally; they are displayed after the entire image
+  // has been loaded.
+
+  // A map of imgIRequests to the nsIFrames that are using them.
+  RequestToFrameMap mRequestToFrameMap;
+
+  // A map of nsIFrames to the imgIRequests they use.
+  FrameToRequestMap mFrameToRequestMap;
+
+  // A weak pointer to our document. Nulled out by DropDocumentReference.
+  nsIDocument* mDocument;
+
+  // The set of all nsCSSValue::Images (whether they're associated a frame or
+  // not).  We'll need this when we go away to remove any requests associated
+  // with our document from those Images.
+  ImageHashSet mImages;
+
+  // Are we cloning?  If so, ignore any notifications we get.
+  bool mInClone;
+};
+
+} // namespace css
+} // namespace mozilla
+
+#endif /* mozilla_css_ImageLoader_h___ */