Bug 1404222 Part 2: Extend ImageLoader to associate flags with each request-frame relationship. r=dbaron

layout/style/ImageLoader.cpp

@@ -77,9 +77,10 @@ ImageLoader::AssociateRequestToFrame(imgIRequest* aRequest,
     });
 
   // Add these to the sets, but only if they're not already there.
-  uint32_t i = frameSet->IndexOfFirstElementGt(aFrame);
-  if (i == 0 || aFrame != frameSet->ElementAt(i-1)) {
-    frameSet->InsertElementAt(i, aFrame);
+  FrameWithFlags fwf(aFrame);
+  uint32_t i = frameSet->IndexOfFirstElementGt(fwf, FrameOnlyComparator());
+  if (i == 0 || aFrame != frameSet->ElementAt(i-1).mFrame) {
+    frameSet->InsertElementAt(i, fwf);
   }
   i = requestSet->IndexOfFirstElementGt(aRequest);
   if (i == 0 || aRequest != requestSet->ElementAt(i-1)) {
@@ -139,7 +140,8 @@ ImageLoader::RemoveRequestToFrameMapping(imgIRequest* aRequest,
   if (auto entry = mRequestToFrameMap.Lookup(aRequest)) {
     FrameSet* frameSet = entry.Data();
     MOZ_ASSERT(frameSet, "This should never be null");
-    frameSet->RemoveElementSorted(aFrame);
+    frameSet->RemoveElementSorted(FrameWithFlags(aFrame),
+                                  FrameOnlyComparator());
     if (frameSet->IsEmpty()) {
       nsPresContext* presContext = GetPresContext();
       if (presContext) {
@@ -362,7 +364,8 @@ ImageLoader::DoRedraw(FrameSet* aFrameSet, bool aForcePaint)
   NS_ASSERTION(aFrameSet, "Must have a frame set");
   NS_ASSERTION(mDocument, "Should have returned earlier!");
 
-  for (nsIFrame* frame : *aFrameSet) {
+  for (FrameWithFlags& fwf : *aFrameSet) {
+    nsIFrame* frame = fwf.mFrame;
     if (frame->StyleVisibility()->IsVisible()) {
       if (frame->IsFrameOfType(nsIFrame::eTablePart)) {
         // Tables don't necessarily build border/background display items
@@ -454,7 +457,8 @@ ImageLoader::OnSizeAvailable(imgIRequest* aRequest, imgIContainer* aImage)
     return NS_OK;
   }
 
-  for (nsIFrame* frame : *frameSet) {
+  for (FrameWithFlags& fwf : *frameSet) {
+    nsIFrame* frame = fwf.mFrame;
     if (frame->StyleVisibility()->IsVisible()) {
       frame->MarkNeedsDisplayItemRebuild();
     }

layout/style/ImageLoader.h

@@ -80,7 +80,35 @@ private:
   // the frame goes away). Thus we maintain hashtables going both ways.  These
   // should always be in sync.
 
-  typedef nsTArray<nsIFrame*> FrameSet;
+  // We also associate flags alongside frames in the request-to-frames hashmap.
+  // These are used for special handling of events for requests.
+  typedef uint32_t FrameFlags;
+
+  struct FrameWithFlags {
+    FrameWithFlags(nsIFrame* aFrame)
+    : mFrame(aFrame),
+      mFlags(0)
+    {
+      MOZ_ASSERT(mFrame);
+    }
+    nsIFrame* const mFrame;
+    FrameFlags mFlags;
+  };
+
+  // A helper class to compare FrameWithFlags by comparing mFrame and
+  // ignoring mFlags.
+  class FrameOnlyComparator {
+    public:
+      bool Equals(const FrameWithFlags& aElem1,
+                  const FrameWithFlags& aElem2) const
+      { return aElem1.mFrame == aElem2.mFrame; }
+
+      bool LessThan(const FrameWithFlags& aElem1,
+                    const FrameWithFlags& aElem2) const
+      { return aElem1.mFrame < aElem2.mFrame; }
+  };
+
+  typedef nsTArray<FrameWithFlags> FrameSet;
   typedef nsTArray<nsCOMPtr<imgIRequest> > RequestSet;
   typedef nsTHashtable<nsPtrHashKey<Image> > ImageHashSet;
   typedef nsClassHashtable<nsISupportsHashKey,