Fixing bug 408792. Remove some expensive QI calls from frequently called code. r=jonas@sicking.cc, sr=bzbarsky@mit.edu

content/base/src/nsDocument.cpp

@@ -1126,7 +1126,7 @@ nsDocument::Init()
   // subclasses currently do, other don't). This is because the code in
   // nsNodeUtils always notifies the first observer first, expecting the
   // first observer to be the document.
-  NS_ENSURE_TRUE(slots->mMutationObservers.PrependElementUnlessExists(this),
+  NS_ENSURE_TRUE(slots->mMutationObservers.PrependElementUnlessExists(static_cast<nsIMutationObserver*>(this)),
                  NS_ERROR_OUT_OF_MEMORY);
 
 
@@ -2585,6 +2585,11 @@ nsDocument::SetScriptGlobalObject(nsIScriptGlobalObject *aScriptGlobalObject)
     mLayoutHistoryState = nsnull;
     mScopeObject = do_GetWeakReference(aScriptGlobalObject);
   }
+
+  // Remember the pointer to our window (or lack there of), to avoid
+  // having to QI every time it's asked for.
+  nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(mScriptGlobalObject);
+  mWindow = window;
 }
 
 nsIScriptGlobalObject*
@@ -2625,6 +2630,10 @@ nsDocument::SetScriptHandlingObject(nsIScriptGlobalObject* aScriptObject)
 nsPIDOMWindow *
 nsDocument::GetWindow()
 {
+  if (mWindow) {
+    return mWindow->GetOuterWindow();
+  }
+
   nsCOMPtr<nsPIDOMWindow> win(do_QueryInterface(GetScriptGlobalObject()));
 
   if (!win) {

content/base/src/nsDocument.h

@@ -747,6 +747,9 @@ protected:
   // document can get its script context and scope. This is the
   // *inner* window object.
   nsCOMPtr<nsIScriptGlobalObject> mScriptGlobalObject;
+  // Weak reference to mScriptGlobalObject QI:d to nsPIDOMWindow,
+  // updated on every set of mSecriptGlobalObject.
+  nsPIDOMWindow *mWindow;
 
   // If document is created for example using
   // document.implementation.createDocument(...), mScriptObject points to

content/html/document/src/nsHTMLDocument.cpp

@@ -3399,7 +3399,7 @@ nsHTMLDocument::ResolveName(const nsAString& aName,
   IdAndNameMapEntry *entry =
     static_cast<IdAndNameMapEntry *>
                (PL_DHashTableOperate(&mIdAndNameHashTable, name,
-                                        PL_DHASH_ADD));
+                                     PL_DHASH_ADD));
   NS_ENSURE_TRUE(entry, NS_ERROR_OUT_OF_MEMORY);
 
   if (entry->mNameContentList == NAME_NOT_VALID) {
@@ -3419,7 +3419,7 @@ nsHTMLDocument::ResolveName(const nsAString& aName,
   // If we already have an entry->mNameContentList, we need to flush out
   // notifications too, so that it will get updated properly.
   FlushPendingNotifications(entry->mNameContentList ?
-                              Flush_ContentAndNotify : Flush_Content);
+                            Flush_ContentAndNotify : Flush_Content);
 
   if (generation != mIdAndNameHashTable.generation) {
     // Table changed, so the entry pointer is no longer valid; look up the
@@ -3428,7 +3428,7 @@ nsHTMLDocument::ResolveName(const nsAString& aName,
     entry =
       static_cast<IdAndNameMapEntry *>
                  (PL_DHashTableOperate(&mIdAndNameHashTable, name,
-                                          PL_DHASH_ADD));
+                                       PL_DHASH_ADD));
     NS_ENSURE_TRUE(entry, NS_ERROR_OUT_OF_MEMORY);
   }
     

dom/src/base/Makefile.in

@@ -129,6 +129,8 @@ LOCAL_INCLUDES = \
 		-I$(topsrcdir)/content/xul/document/src \
 		-I$(topsrcdir)/content/events/src \
 		-I$(topsrcdir)/content/base/src \
+		-I$(topsrcdir)/content/html/document/src \
+		-I$(topsrcdir)/layout/style \
 		$(NULL)
 
 DEFINES += -D_IMPL_NS_LAYOUT

dom/src/base/nsDOMClassInfo.cpp

@@ -132,7 +132,7 @@
 #include "nsIDOMHTMLFormElement.h"
 #include "nsIDOMNSHTMLFormControlList.h"
 #include "nsIDOMHTMLCollection.h"
-#include "nsIHTMLDocument.h"
+#include "nsHTMLDocument.h"
 
 // HTMLSelectElement helper includes
 #include "nsIDOMHTMLSelectElement.h"
@@ -7667,8 +7667,9 @@ nsHTMLDocumentSH::ResolveImpl(JSContext *cx,
                               nsIXPConnectWrappedNative *wrapper, jsval id,
                               nsISupports **result)
 {
-  nsCOMPtr<nsIHTMLDocument> doc(do_QueryWrappedNative(wrapper));
-  NS_ENSURE_TRUE(doc, NS_ERROR_UNEXPECTED);
+  nsHTMLDocument *doc =
+    static_cast<nsHTMLDocument*>(static_cast<nsINode*>
+                                 (wrapper->Native()));
 
   // 'id' is not always a string, it can be a number since document.1
   // should map to <input name="1">. Thus we can't use
@@ -8252,7 +8253,7 @@ nsHTMLDocumentSH::NewResolve(nsIXPConnectWrappedNative *wrapper, JSContext *cx,
 
     if (id == sAll_id && !sDisableDocumentAllSupport &&
         !ObjectIsNativeWrapper(cx, obj)) {
-      nsCOMPtr<nsIDocument> doc(do_QueryWrappedNative(wrapper));
+      nsIDocument *doc = static_cast<nsIDocument*>(wrapper->Native());
 
       if (doc->GetCompatibilityMode() == eCompatibility_NavQuirks) {
         JSObject *helper =