Prepare a bunch of ash tests for workspace2. With Workspace2 you can't

ash/wm/workspace/workspace_manager.cc

Index: ash/wm/workspace/workspace_manager.cc
diff --git a/ash/wm/workspace/workspace_manager.cc b/ash/wm/workspace/workspace_manager.cc
index aac67bc4c8ee16bbad91242e00161b40fd96d22c..db799c40aaf3b956dd24636d72cee3e59197e214 100644
--- a/ash/wm/workspace/workspace_manager.cc
+++ b/ash/wm/workspace/workspace_manager.cc
@@ -134,6 +134,10 @@ void WorkspaceManager::SetActiveWorkspaceByWindow(aura::Window* window) {
     workspace->Activate();
 }
 
+void WorkspaceManager::SetGridSize(int grid_size) {
+  grid_size_ = grid_size;
+}
+
 void WorkspaceManager::UpdateShelfVisibility() {
   if (shelf_)
     shelf_->UpdateVisibilityState();