Wires up immersive mode for chrome and mash

services/ui/ws/window_manager_state.cc

Index: services/ui/ws/window_manager_state.cc
diff --git a/services/ui/ws/window_manager_state.cc b/services/ui/ws/window_manager_state.cc
index 224207202adc95319a720e7aab3b604d6d27c146..3738a6b61c158fb696cf0bfc3d5d7b6fc949b8fc 100644
--- a/services/ui/ws/window_manager_state.cc
+++ b/services/ui/ws/window_manager_state.cc
@@ -507,15 +507,15 @@ ClientSpecificId WindowManagerState::GetEventTargetClientId(
   // the window.
   WindowTree* tree = nullptr;
   if (in_nonclient_area) {
-    tree = window_server()->GetTreeWithId(window->id().client_id);
+    // Events in the non-client area always go to the window manager.
+    tree = window_tree_;
   } else {
     // If the window is an embed root, forward to the embedded window.
     tree = window_server()->GetTreeWithRoot(window);
     if (!tree)
       tree = window_server()->GetTreeWithId(window->id().client_id);
-  }
+    DCHECK(tree);
 
-  if (tree) {
     const ServerWindow* embed_root =
         tree->HasRoot(window) ? window : GetEmbedRoot(window);
     while (tree && tree->embedder_intercepts_events()) {
@@ -523,11 +523,7 @@ ClientSpecificId WindowManagerState::GetEventTargetClientId(
       tree = window_server()->GetTreeWithId(embed_root->id().client_id);
       embed_root = GetEmbedRoot(embed_root);
     }
-  }
-
-  if (!tree) {
-    DCHECK(in_nonclient_area);
-    tree = window_tree_;
+    DCHECK(tree);
   }
   return tree->id();
 }