Do not use ProjectRootManagerImpl in StartupManagerImpl

IDEA-199211 Refactor code dependent on project model implementation
IDEA-CR-37149

platform/platform-impl/src/com/intellij/ide/startup/impl/StartupManagerImpl.java

@@ -18,7 +18,7 @@ import com.intellij.openapi.project.DumbServiceImpl;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.project.impl.ProjectLifecycleListener;
 import com.intellij.openapi.roots.ProjectRootManager;
-import com.intellij.openapi.roots.impl.ProjectRootManagerImpl;
+import com.intellij.openapi.roots.ex.ProjectRootManagerEx;
 import com.intellij.openapi.startup.StartupActivity;
 import com.intellij.openapi.util.SystemInfo;
 import com.intellij.openapi.util.io.FileUtil;
@@ -225,7 +225,7 @@ public class StartupManagerImpl extends StartupManagerEx {
       if (myProject.isDisposed() || myInitialRefreshScheduled) return;
 
       myInitialRefreshScheduled = true;
-      ((ProjectRootManagerImpl)ProjectRootManager.getInstance(myProject)).markRootsForRefresh();
+      ProjectRootManagerEx.getInstanceEx(myProject).markRootsForRefresh();
 
       Application app = ApplicationManager.getApplication();
       if (!app.isCommandLine()) {

platform/projectModel-api/src/com/intellij/openapi/roots/ex/ProjectRootManagerEx.java

@@ -33,6 +33,8 @@ public abstract class ProjectRootManagerEx extends ProjectRootManager {
   // invokes runnable surrounded by beforeRootsChange()/rootsChanged() callbacks
   public abstract void makeRootsChange(@NotNull Runnable runnable, boolean fileTypes, boolean fireEvents);
 
+  public abstract void markRootsForRefresh();
+
   public abstract void mergeRootsChangesDuring(@NotNull Runnable runnable);
 
   public abstract void clearScopesCachesForModules();

platform/projectModel-impl/src/com/intellij/openapi/roots/impl/ProjectRootManagerImpl.java

@@ -641,7 +641,10 @@ public class ProjectRootManagerImpl extends ProjectRootManagerEx implements Pers
     }
   }
 
-  public void markRootsForRefresh() { }
+  @Override
+  public void markRootsForRefresh() {
+
+  }
 
   @NotNull
   public VirtualFilePointerListener getRootsValidityChangedListener() {