Fix for bug 659580 (Flush CanvasImageCache on shutdown). r=roc.

--HG--
extra : rebase_source : 9752189ce8c9bd13795979cfa8d50311b5bf5b56

content/canvas/src/CanvasImageCache.cpp

@@ -133,6 +133,13 @@ public:
 
 static ImageCache* gImageCache = nsnull;
 
+class CanvasImageCacheShutdownObserver : public nsIObserver
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+};
+
 void
 CanvasImageCache::NotifyDrawImage(nsIDOMElement* aImage,
                                   nsHTMLCanvasElement* aCanvas,
@@ -142,6 +149,7 @@ CanvasImageCache::NotifyDrawImage(nsIDOMElement* aImage,
 {
   if (!gImageCache) {
     gImageCache = new ImageCache();
+    nsContentUtils::RegisterShutdownObserver(new CanvasImageCacheShutdownObserver());
   }
 
   ImageCacheEntry* entry = gImageCache->mCache.PutEntry(ImageCacheKey(aImage, aCanvas));
@@ -186,11 +194,21 @@ CanvasImageCache::Lookup(nsIDOMElement* aImage,
   return entry->mData->mSurface;
 }
 
-void
+NS_IMPL_ISUPPORTS1(CanvasImageCacheShutdownObserver, nsIObserver)
-CanvasImageCache::Shutdown()
+
+NS_IMETHODIMP
+CanvasImageCacheShutdownObserver::Observe(nsISupports *aSubject,
+                                          const char *aTopic,
+                                          const PRUnichar *aData)
 {
-  delete gImageCache;
+  if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
-  gImageCache = nsnull;
+    delete gImageCache;
+    gImageCache = nsnull;
+
+    nsContentUtils::UnregisterShutdownObserver(this);
+  }
+
+  return NS_OK;
 }
 
 }

content/canvas/src/CanvasImageCache.h

@@ -69,8 +69,6 @@ public:
   static gfxASurface* Lookup(nsIDOMElement* aImage,
                              nsHTMLCanvasElement* aCanvas,
                              gfxIntSize* aSize);
-
-  static void Shutdown();
 };
 
 }

layout/build/nsLayoutStatics.cpp

@@ -121,7 +121,6 @@
 #include "nsContentSink.h"
 #include "nsFrameMessageManager.h"
 #include "nsRefreshDriver.h"
-#include "CanvasImageCache.h"
 
 #include "nsHyphenationManager.h"
 
@@ -281,7 +280,6 @@ nsLayoutStatics::Initialize()
 void
 nsLayoutStatics::Shutdown()
 {
-  CanvasImageCache::Shutdown();
   nsFrameScriptExecutor::Shutdown();
   nsFocusManager::Shutdown();
 #ifdef MOZ_XUL