Tracker: Use queries to find transient queries to delete.

Walking the entire filesystem is slow and wastes cache memory.
Instead, just use a TQueryWalker to find and iterate over queries.

src/kits/tracker/FindPanel.cpp

@@ -3678,13 +3678,11 @@ DeleteTransientQueriesTask::Initialize()
 		state = kError;
 		return;
 	}
-	fWalker = new BTrackerPrivate::TNodeWalker(path.Path());
+	fWalker = new BTrackerPrivate::TQueryWalker(kAttrQueryLastChange " != 0");
 	state = kAllocatedWalker;
 }
 
 
-const int32 kBatchCount = 100;
-
 bool
 DeleteTransientQueriesTask::GetSome()
 {
@@ -3707,10 +3705,8 @@ DeleteTransientQueriesTask::GetSome()
 }
 
 
-const int32 kDaysToExpire = 7;
+bool
-
+DeleteTransientQueriesTask::QueryOldEnough(Model* model)
-static bool
-QueryOldEnough(Model* model)
 {
 	// check if it is old and ready to be deleted
 	time_t now = time(0);

src/kits/tracker/FindPanel.h

@@ -370,11 +370,16 @@ protected:
 				kError
 			};
 
+			static bool			QueryOldEnough(Model* model);
+
 protected:
 			State 				state;
 
 private:
-			BTrackerPrivate::TNodeWalker* fWalker;
+			static const int32 kBatchCount = 100;
+			static const int32 kDaysToExpire = 7;
+
+			BTrackerPrivate::TQueryWalker* fWalker;
 };