378327 - minor cleanup/simplification of ForwardReferences code in nsXULDocument

- move AddForwardReference and ResolveForwardReferences from nsIXULDocument to
nsXULDocument, make them non-virtual.
- make mForwardReferences an nsTArray<nsAutoPtr<nsForwardReference> > instead
of nsAutoVoidArray.

r=smaug, sr=roc

content/xul/document/public/nsIXULDocument.h

@@ -42,22 +42,15 @@
 #include "nsString.h"
 #include "nsCOMArray.h"
 
-class nsForwardReference;
-class nsIAtom;
-class nsIDOMElement;
-class nsIPrincipal;
-class nsIRDFResource;
-class nsISupportsArray;
 class nsIXULTemplateBuilder;
-class nsIURI;
 class nsIContent;
-class nsIRDFDataSource;
 class nsIScriptGlobalObjectOwner;
 
-// {01c4fe87-961f-4194-a21d-04f4387c4bb3}
+
+// {57314526-f749-4cf0-b6b6-3723eba21480}
 #define NS_IXULDOCUMENT_IID \
-{ 0x01c4fe87, 0x961f, 0x4194, \
-  { 0xa2, 0x1d, 0x04, 0xf4, 0x38, 0x7c, 0x4b, 0xb3 } }
+{ 0x57314526, 0xf749, 0x4cf0, \
+  { 0xb6, 0xb6, 0x37, 0x23, 0xeb, 0xa2, 0x14, 0x80 } }
 
 
 /*
@@ -90,17 +83,6 @@ public:
    */
   NS_IMETHOD GetElementsForID(const nsAString& aID, nsCOMArray<nsIContent>& aElements) = 0;
 
-  /**
-   * Add a "forward declaration" of a XUL observer. Such declarations
-   * will be resolved when document loading completes.
-   */
-  NS_IMETHOD AddForwardReference(nsForwardReference* aForwardReference) = 0;
-
-  /**
-   * Resolve the all of the document's forward references.
-   */
-  NS_IMETHOD ResolveForwardReferences() = 0;
-
   /**
    * Get the nsIScriptGlobalObjectOwner for this document.
    */

content/xul/document/src/nsXULDocument.cpp

@@ -218,7 +218,7 @@ nsXULDocument::~nsXULDocument()
 
     // In case we failed somewhere early on and the forward observer
     // decls never got resolved.
-    DestroyForwardReferences();
+    mForwardReferences.Clear();
 
     // Destroy our broadcaster map.
     if (mBroadcasterMap) {
@@ -1070,11 +1070,14 @@ nsXULDocument::GetElementsForID(const nsAString& aID,
     return NS_OK;
 }
 
-NS_IMETHODIMP
+nsresult
 nsXULDocument::AddForwardReference(nsForwardReference* aRef)
 {
     if (mResolutionPhase < aRef->GetPhase()) {
-        mForwardReferences.AppendElement(aRef);
+        if (!mForwardReferences.AppendElement(aRef)) {
+            delete aRef;
+            return NS_ERROR_OUT_OF_MEMORY;
+        }
     }
     else {
         NS_ERROR("forward references have already been resolved");
@@ -1085,7 +1088,7 @@ nsXULDocument::AddForwardReference(nsForwardReference* aRef)
 }
 
 
-NS_IMETHODIMP
+nsresult
 nsXULDocument::ResolveForwardReferences()
 {
     if (mResolutionPhase == nsForwardReference::eDone)
@@ -1099,12 +1102,13 @@ nsXULDocument::ResolveForwardReferences()
 
     const nsForwardReference::Phase* pass = nsForwardReference::kPasses;
     while ((mResolutionPhase = *pass) != nsForwardReference::eDone) {
-        PRInt32 previous = 0;
-        while (mForwardReferences.Count() && mForwardReferences.Count() != previous) {
-            previous = mForwardReferences.Count();
+        PRUint32 previous = 0;
+        while (mForwardReferences.Length() &&
+               mForwardReferences.Length() != previous) {
+            previous = mForwardReferences.Length();
 
-            for (PRInt32 i = 0; i < mForwardReferences.Count(); ++i) {
-                nsForwardReference* fwdref = NS_REINTERPRET_CAST(nsForwardReference*, mForwardReferences[i]);
+            for (PRUint32 i = 0; i < mForwardReferences.Length(); ++i) {
+                nsForwardReference* fwdref = mForwardReferences[i];
 
                 if (fwdref->GetPhase() == *pass) {
                     nsForwardReference::Result result = fwdref->Resolve();
@@ -1113,7 +1117,6 @@ nsXULDocument::ResolveForwardReferences()
                     case nsForwardReference::eResolve_Succeeded:
                     case nsForwardReference::eResolve_Error:
                         mForwardReferences.RemoveElementAt(i);
-                        delete fwdref;
 
                         // fixup because we removed from list
                         --i;
@@ -1130,7 +1133,7 @@ nsXULDocument::ResolveForwardReferences()
         ++pass;
     }
 
-    DestroyForwardReferences();
+    mForwardReferences.Clear();
     return NS_OK;
 }
 
@@ -1367,21 +1370,6 @@ nsXULDocument::Persist(nsIContent* aElement, PRInt32 aNameSpaceID,
 }
 
 
-
-nsresult
-nsXULDocument::DestroyForwardReferences()
-{
-    for (PRInt32 i = mForwardReferences.Count() - 1; i >= 0; --i) {
-        nsForwardReference* fwdref =
-            NS_REINTERPRET_CAST(nsForwardReference*, mForwardReferences[i]);
-        delete fwdref;
-    }
-
-    mForwardReferences.Clear();
-    return NS_OK;
-}
-
-
 nsresult
 nsXULDocument::GetPixelDimensions(nsIPresShell* aShell, PRInt32* aWidth,
                                   PRInt32* aHeight)

content/xul/document/src/nsXULDocument.h

@@ -136,8 +136,7 @@ public:
     NS_IMETHOD RemoveElementForID(const nsAString& aID, nsIContent* aElement);
     NS_IMETHOD GetElementsForID(const nsAString& aID,
                                 nsCOMArray<nsIContent>& aElements);
-    NS_IMETHOD AddForwardReference(nsForwardReference* aRef);
-    NS_IMETHOD ResolveForwardReferences();
+
     NS_IMETHOD GetScriptGlobalObjectOwner(nsIScriptGlobalObjectOwner** aGlobalOwner);
     NS_IMETHOD AddSubtreeToDocument(nsIContent* aElement);
     NS_IMETHOD RemoveSubtreeFromDocument(nsIContent* aElement);
@@ -255,9 +254,6 @@ protected:
     nsresult
     Persist(nsIContent* aElement, PRInt32 aNameSpaceID, nsIAtom* aAttribute);
 
-    nsresult
-    DestroyForwardReferences();
-
     // IMPORTANT: The ownership implicit in the following member
     // variables has been explicitly checked and set using nsCOMPtr
     // for owning pointers and raw COM interface pointers for weak
@@ -297,9 +293,6 @@ protected:
         BuilderTable;
     BuilderTable* mTemplateBuilderTable;
 
-    nsVoidArray mForwardReferences;
-    nsForwardReference::Phase mResolutionPhase;
-
     PRUint32 mPendingSheets;
 
     /*
@@ -434,6 +427,35 @@ protected:
      */
     nsresult AddPrototypeSheets();
 
+
+protected:
+    /* Declarations related to forward references. 
+     *
+     * Forward references are declarations which are added to the temporary
+     * list (mForwardReferences) during the document (or overlay) load and
+     * are resolved later, when the document loading is almost complete.
+     */
+
+    /**
+     * The list of different types of forward references to resolve. After
+     * a reference is resolved, it is removed from this array (and
+     * automatically deleted)
+     */
+    nsTArray<nsAutoPtr<nsForwardReference> > mForwardReferences;
+
+    /** Indicates what kind of forward references are still to be processed. */
+    nsForwardReference::Phase mResolutionPhase;
+
+    /**
+     * Adds aRef to the mForwardReferences array. Takes the ownership of aRef.
+     */
+    nsresult AddForwardReference(nsForwardReference* aRef);
+
+    /**
+     * Resolve all of the document's forward references.
+     */
+    nsresult ResolveForwardReferences();
+
     /**
      * Used to resolve broadcaster references
      */