Add support to the UI Service to run it inside the browser's process.

services/ui/ws/user_display_manager.cc

Index: services/ui/ws/user_display_manager.cc
diff --git a/services/ui/ws/user_display_manager.cc b/services/ui/ws/user_display_manager.cc
index f52663fbb4c1d4dc9f0b2ef080fd9e2bfb32a639..e432999903ae634e44e15d5b02a90d405c347d8f 100644
--- a/services/ui/ws/user_display_manager.cc
+++ b/services/ui/ws/user_display_manager.cc
@@ -6,9 +6,10 @@
 
 #include <utility>
 
+#include "services/ui/display/screen_manager.h"
 #include "services/ui/ws/user_display_manager_delegate.h"
 #include "ui/display/display.h"
-#include "ui/display/screen.h"
+#include "ui/display/screen_base.h"
 #include "ui/display/types/display_constants.h"
 
 namespace ui {
@@ -95,7 +96,8 @@ mojom::WsDisplayPtr UserDisplayManager::ToWsDisplayPtr(
 }
 
 std::vector<mojom::WsDisplayPtr> UserDisplayManager::GetAllDisplays() {
-  const auto& displays = display::Screen::GetScreen()->GetAllDisplays();
+  const auto& displays =
+      display::ScreenManager::GetInstance()->GetScreen()->GetAllDisplays();
 
   std::vector<mojom::WsDisplayPtr> ws_display;
   ws_display.reserve(displays.size());
@@ -107,8 +109,10 @@ std::vector<mojom::WsDisplayPtr> UserDisplayManager::GetAllDisplays() {
 }
 
 bool UserDisplayManager::ShouldCallOnDisplaysChanged() const {
-  return got_valid_frame_decorations_ &&
-         !display::Screen::GetScreen()->GetAllDisplays().empty();
+  return got_valid_frame_decorations_ && !display::ScreenManager::GetInstance()
+                                              ->GetScreen()
+                                              ->GetAllDisplays()
+                                              .empty();
 }
 
 void UserDisplayManager::CallOnDisplaysChangedIfNecessary() {
@@ -120,9 +124,12 @@ void UserDisplayManager::CallOnDisplaysChangedIfNecessary() {
 
 void UserDisplayManager::CallOnDisplaysChanged(
     mojom::DisplayManagerObserver* observer) {
-  observer->OnDisplaysChanged(
-      GetAllDisplays(), display::Screen::GetScreen()->GetPrimaryDisplay().id(),
-      GetInternalDisplayId());
+  observer->OnDisplaysChanged(GetAllDisplays(),
+                              display::ScreenManager::GetInstance()
+                                  ->GetScreen()
+                                  ->GetPrimaryDisplay()
+                                  .id(),
+                              GetInternalDisplayId());
 }
 
 }  // namespace ws