ProjectTree: Add a way to register managers for subtrees

Change-Id: I4694bb7dbe75b67946cdb5d8ca8b5a3ff1e40659
Reviewed-by: hjk <hjk@qt.io>

src/plugins/projectexplorer/project.cpp

@@ -41,6 +41,7 @@
 #include <coreplugin/icore.h>
 #include <projectexplorer/buildmanager.h>
 #include <projectexplorer/kitmanager.h>
+#include <projectexplorer/projecttree.h>
 
 #include <utils/algorithm.h>
 #include <utils/macroexpander.h>
@@ -430,6 +431,8 @@ void Project::setRootProjectNode(ProjectNode *root)
     if (d->m_rootProjectNode == root)
         return;
 
+    ProjectTree::applyTreeManager(root);
+
     d->m_rootProjectNode = root;
     emit projectTreeChanged(this, QPrivateSignal());
     // Do not delete oldNode! The ProjectTree owns that!