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 d65aad95cc2956f4483abc724410dff025e79d4c..07bb578a9e0e476ad4ac9d36e256e9ea9b6bd9a3 100644
--- a/ash/mus/window_manager.cc
+++ b/ash/mus/window_manager.cc
@@ -368,12 +368,11 @@ void WindowManager::SetWindowManagerClient(aura::WindowManagerClient* client) {
   window_manager_client_ = client;
 }
 
-bool WindowManager::OnWmSetBounds(aura::Window* window, gfx::Rect* bounds) {
+void 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;
 }
 
 bool WindowManager::OnWmSetProperty(