Basic display management for mus

components/mus/mus_app.cc

Index: components/mus/mus_app.cc
diff --git a/components/mus/mus_app.cc b/components/mus/mus_app.cc
index be7350fb566ba52e4959a2ada0461ffcf827ee93..ece8f325e15ce8fe079a48b29dc50fa034c93bf8 100644
--- a/components/mus/mus_app.cc
+++ b/components/mus/mus_app.cc
@@ -17,6 +17,7 @@
 #include "components/mus/ws/display.h"
 #include "components/mus/ws/display_binding.h"
 #include "components/mus/ws/display_manager.h"
+#include "components/mus/ws/platform_screen.h"
 #include "components/mus/ws/user_display_manager.h"
 #include "components/mus/ws/window_server.h"
 #include "components/mus/ws/window_server_test_impl.h"
@@ -70,7 +71,10 @@ struct MandolineUIServicesApp::UserState {
   std::unique_ptr<ws::WindowTreeHostFactory> window_tree_host_factory;
 };
 
-MandolineUIServicesApp::MandolineUIServicesApp() : test_config_(false) {}
+MandolineUIServicesApp::MandolineUIServicesApp()
+    : test_config_(false),
+      platform_screen_(new ws::PlatformScreen()),
+      weak_ptr_factory_(this) {}
 
 MandolineUIServicesApp::~MandolineUIServicesApp() {
   // Destroy |window_server_| first, since it depends on |event_source_|.
@@ -170,6 +174,9 @@ void MandolineUIServicesApp::Initialize(shell::Connector* connector,
   // TODO(rjkroege): It is possible that we might want to generalize the
   // GpuState object.
   platform_display_init_params_.gpu_state = new GpuState();
+
+  // Gpu must be running before the PlatformScreen can be initialized.
+  platform_screen_->Init();
   window_server_.reset(
       new ws::WindowServer(this, platform_display_init_params_.surfaces_state));
 }
@@ -203,13 +210,25 @@ bool MandolineUIServicesApp::IsTestConfig() const {
   return test_config_;
 }
 
-void MandolineUIServicesApp::CreateDefaultDisplays() {
+void MandolineUIServicesApp::CreatePhysicalDisplayCallback(int64_t id,

[sky, 2016/05/03 02:39:50]

Make position match that of header.

[rjkroege, 2016/05/03 21:03:03]

Done.

+                                                           gfx::Rect bounds) {
+  platform_display_init_params_.display_bounds = bounds;
+  platform_display_init_params_.display_id = id;
+
   // Display manages its own lifetime.
   ws::Display* host_impl =
       new ws::Display(window_server_.get(), platform_display_init_params_);
   host_impl->Init(nullptr);
 }
 
+void MandolineUIServicesApp::CreateDefaultDisplays() {
+  // An asynchronous callback will create the Displays once the physical
+  // displays are ready.
+  platform_screen_->ConfigurePhysicalDisplay(
+      base::Bind(&MandolineUIServicesApp::CreatePhysicalDisplayCallback,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
 void MandolineUIServicesApp::Create(shell::Connection* connection,
                                     mojom::DisplayManagerRequest request) {
   window_server_->display_manager()