Change the delay for how often we synchronize solutions

Now that we're doing all the WorkspaceChanged notifications on
background threads, that means the notifications won't be quite as
batched as before; this was causing an increase in synchronizations
that was creating some wasted work.

Author: jasonmalinowski

src/EditorFeatures/Core/Remote/SolutionChecksumUpdater.cs

@@ -58,8 +58,13 @@ public SolutionChecksumUpdater(
 
         _shutdownToken = shutdownToken;
 
+        // A time span of Short is chosen here to ensure that the batching favors fewer but larger batches.
+        // During solution load a large number of WorkspaceChange events might be raised over a few seconds,
+        // and in performance tests a 50ms delay was found to be causing a lot of extra memory churn synchronizing
+        // things OOP. Short didn't cause a similar issue; it's possible this will need to be fine tuned for something in
+        // the middle.
         _synchronizeWorkspaceQueue = new AsyncBatchingWorkQueue(
-            DelayTimeSpan.NearImmediate,
+            DelayTimeSpan.Short,
             SynchronizePrimaryWorkspaceAsync,
             listener,
             shutdownToken);