IDEA-163026 AutoScrollFromSource delay is unconfigurable, and unpleasant

platform/platform-api/src/com/intellij/ui/AutoScrollFromSourceHandler.java

@@ -28,6 +28,7 @@ import com.intellij.openapi.fileEditor.FileEditorManagerListener;
 import com.intellij.openapi.project.DumbAware;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Disposer;
+import com.intellij.openapi.util.registry.Registry;
 import com.intellij.util.Alarm;
 import com.intellij.util.messages.MessageBusConnection;
 import org.jetbrains.annotations.NotNull;
@@ -69,7 +70,7 @@ public abstract class AutoScrollFromSourceHandler implements Disposable {
   }
 
   protected long getAlarmDelay() {
-    return 500;
+    return Registry.intValue("ide.autoscroll.from.source.delay", 100);
   }
 
   public void install() {

platform/util/resources/misc/registry.properties

@@ -113,6 +113,9 @@ ide.tree.deferred.icon.invalidates.cache=true
 
 ide.splitter.mouseZone=6
 
+ide.autoscroll.from.source.delay=100
+ide.autoscroll.from.source.delay.description=Delay before performing the AutoscrollFromSource action
+
 ide.scroll.default.unit.increment=false
 ide.scroll.default.unit.increment.description=Use default unit increment from Java (may decrease scrolling performance).