Update bool WindowManager::OnWmSetBounds() to match with its desirable behavior.

ash/mus/window_manager.cc

Index: ash/mus/window_manager.cc
diff --git a/ash/mus/window_manager.cc b/ash/mus/window_manager.cc
index 53f0f6763bff8654f9cc087dcb2c7678d8efc7f6..7956210670b59c1640a94c1fdf49f6d67a30b057 100644
--- a/ash/mus/window_manager.cc
+++ b/ash/mus/window_manager.cc
@@ -371,12 +371,9 @@ void WindowManager::SetWindowManagerClient(aura::WindowManagerClient* client) {
   window_manager_client_ = client;
 }
 
-bool WindowManager::OnWmSetBounds(aura::Window* window, gfx::Rect* bounds) {
-  // TODO(sky): this indirectly sets bounds, which is against what
-  // OnWmSetBounds() recommends doing. Remove that restriction, or fix this.
-  WmWindowMus::Get(window)->SetBounds(*bounds);
-  *bounds = window->bounds();
-  return true;
+void WindowManager::OnWmSetBounds(aura::Window* window,
+                                  const gfx::Rect& bounds) {
+  WmWindowMus::Get(window)->SetBounds(bounds);
 }
 
 bool WindowManager::OnWmSetProperty(