Work on 49212 and 17470. Add start/stop notifications for perf improvement for

Mark All Read and Delete large number of messages. r=bienvenu.

mailnews/base/public/nsIMsgFolder.idl

@@ -330,4 +330,13 @@ const nsMsgBiffState nsMsgBiffState_Unknown = 2; // We dunno whether there is ne
   nsIMsgDatabase getDBFolderInfoAndDB(out nsIDBFolderInfo folderInfo);
 
 	nsIMsgFolder getChildWithURI(in string uri, in boolean deep);
+
+	/**
+	 *	Turn notifications on/off for various notification types. Currently only supporting
+	 *  allMessageCountNotifications which refers to both total and unread message counts.
+	 */
+	const unsigned long allMessageCountNotifications    = 0;
+
+	void enableNotifications(in long notificationType, in boolean enable);
+
 };

mailnews/base/util/nsMsgFolder.cpp

@@ -94,7 +94,8 @@ nsMsgFolder::nsMsgFolder(void)
     mIsServerIsValid(PR_FALSE),
     mIsServer(PR_FALSE),
     mDeleteIsMoveToTrash(PR_TRUE),
-    mBaseMessageURI(nsnull)
+    mBaseMessageURI(nsnull),
+	mNotifyCountChanges(PR_TRUE)
 	{
 //  NS_INIT_REFCNT(); done by superclass
 
@@ -2213,6 +2214,10 @@ nsMsgFolder::NotifyUnicharPropertyChanged(nsIAtom *property,
 
 nsresult nsMsgFolder::NotifyIntPropertyChanged(nsIAtom *property, PRInt32 oldValue, PRInt32 newValue)
 {
+	//Don't send off count notifications if they are turned off.
+	if(!mNotifyCountChanges && ((property == kTotalMessagesAtom) ||( property ==  kTotalUnreadMessagesAtom)))
+		return NS_OK;
+
 	nsCOMPtr<nsISupports> supports;
 	if(NS_SUCCEEDED(QueryInterface(NS_GET_IID(nsISupports), getter_AddRefs(supports))))
 	{
@@ -2400,3 +2405,18 @@ nsMsgFolder::GetFilterList(nsIMsgFilterList **aResult)
 
   return server->GetFilterList(aResult);
 }
+
+/* void enableNotifications (in long notificationType, in boolean enable); */
+NS_IMETHODIMP nsMsgFolder::EnableNotifications(PRInt32 notificationType, PRBool enable)
+{
+	if(notificationType == nsIMsgFolder::allMessageCountNotifications)
+	{
+		mNotifyCountChanges = enable;
+		if(enable)
+			UpdateSummaryTotals(PR_TRUE);
+		return NS_OK;
+	}
+	return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+

mailnews/base/util/nsMsgFolder.h

@@ -167,6 +167,7 @@ public:
   NS_IMETHOD MarkThreadRead(nsIMsgThread *thread);
 
   NS_IMETHOD GetChildWithURI(const char *uri, PRBool deep, nsIMsgFolder **_retval); 
+  NS_IMETHOD EnableNotifications(PRInt32 notificationType, PRBool enable);
 
   // end NS_DECL_NSIMSGFOLDER
   
@@ -237,6 +238,7 @@ protected:
                                          unknown; -2 means unknown but we already
                                          tried to find out.) */
   PRInt32 mNumTotalMessages;         /* count of existing messages. */
+  PRBool mNotifyCountChanges;
   PRUint32 mExpungedBytes;
   nsCOMPtr<nsISupportsArray> mSubFolders;
   nsVoidArray *mListeners; //This can't be an nsISupportsArray because due to