Converts mash to use Shell

ash/mus/root_window_controller.cc

Index: ash/mus/root_window_controller.cc
diff --git a/ash/mus/root_window_controller.cc b/ash/mus/root_window_controller.cc
index 53f9a19b392f2a3506cf91a76bc9a59829ae026c..360fc29131265dd29744024f5606315008cffe5b 100644
--- a/ash/mus/root_window_controller.cc
+++ b/ash/mus/root_window_controller.cc
@@ -76,13 +76,15 @@ RootWindowController::RootWindowController(
       window_tree_host_(window_tree_host.get()),
       window_count_(0),
       display_(display) {
-  ash::InitRootWindowSettings(window_tree_host->window());
+  ash::InitRootWindowSettings(window_tree_host->window())->display_id =

[James Cook, 2017/01/18 01:00:24]

nit: This would be clearer if the result of InitRootWindowSettings() went into a
local variable.

[sky, 2017/01/18 04:00:07]

Done.

+      display.id();
   window_tree_host->window()->SetProperty(kRootWindowControllerKey, this);
-  WmShellMus::Get()->AddRootWindowController(this);
   ash_root_window_controller_ = base::WrapUnique(
       new ash::RootWindowController(nullptr, window_tree_host.release()));
   ash_root_window_controller_->Init(root_window_type);
 
+  // TODO: To avoid lots of IPC AddActivationParent() should take an array.
+  // http://crbug.com/682048.
   for (size_t i = 0; i < kNumActivatableShellWindowIds; ++i) {
     window_manager_->window_manager_client()->AddActivationParent(
         GetWindowByShellWindowId(kActivatableShellWindowIds[i])->aura_window());
@@ -92,7 +94,6 @@ RootWindowController::RootWindowController(
 RootWindowController::~RootWindowController() {
   Shutdown();
   ash_root_window_controller_.reset();
-  WmShellMus::Get()->RemoveRootWindowController(this);
 }
 
 // static