Two tweaks to improve better shadows/activation

. Only create the NonClientFrameController for windows in the user
  container. This is temporary, need to plumb through types to know
  whether the window should have a frame.
. In general we don't want the widgets created by the wm to change
  focus at the mus level. Instead we want to funnel requests to mus
  and then update the widget state from mus. So, create the widgets in
  such a way that they don't automatically focus.

BUG=none
TEST=none
R=ben@chromium.org

Review URL: https://codereview.chromium.org/1504503002

Cr-Commit-Position: refs/heads/master@{#363501}

mash/wm/non_client_frame_controller.cc

@@ -157,10 +157,12 @@ NonClientFrameController::NonClientFrameController(
   window_->AddObserver(this);
 
   views::Widget::InitParams params(views::Widget::InitParams::TYPE_WINDOW);
+  // We initiate focus at the mus level, not at the views level.
+  params.activatable = views::Widget::InitParams::ACTIVATABLE_NO;
   params.delegate = this;
   params.native_widget = new WmNativeWidgetMus(widget_, shell, window);
   widget_->Init(params);
-  widget_->Show();
+  widget_->ShowInactive();
 
   const int shadow_inset =
       Shadow::GetInteriorInsetForStyle(Shadow::STYLE_ACTIVE);

mash/wm/window_manager_impl.cc

@@ -108,9 +108,13 @@ void WindowManagerImpl::OpenWindow(
   state_->GetWindowForContainer(container)->AddChild(child_window);
   child_window->Embed(client.Pass());
 
-  // NonClientFrameController deletes itself when |child_window| is destroyed.
-  new NonClientFrameController(state_->app()->shell(), child_window,
-                               state_->window_tree_host());
+  // TODO(sky): we need more sophisticated heuristics as to when the non-client
+  // frame is necessary.
+  if (container == mojom::CONTAINER_USER_WINDOWS) {
+    // NonClientFrameController deletes itself when |child_window| is destroyed.
+    new NonClientFrameController(state_->app()->shell(), child_window,
+                                 state_->window_tree_host());
+  }
 
   state_->IncrementWindowCount();
 }