Add GetDisplayWithDisplayId to display::Screen.

headless/lib/browser/headless_screen.cc

Index: headless/lib/browser/headless_screen.cc
diff --git a/headless/lib/browser/headless_screen.cc b/headless/lib/browser/headless_screen.cc
index c8be18bfdb1804dab9c759e8c04d70a924dcdd2b..1d90a5bbce1374edac188c02a5320a143becc14a 100644
--- a/headless/lib/browser/headless_screen.cc
+++ b/headless/lib/browser/headless_screen.cc
@@ -140,6 +140,15 @@ std::vector<display::Display> HeadlessScreen::GetAllDisplays() const {
   return std::vector<display::Display>(1, display_);
 }
 
+bool HeadlessScreen::GetDisplayWithDisplayId(int64_t display_id,
+                                             display::Display* display) const {
+  if (display_.id() == display_id) {
+    *display = display_;
+    return true;
+  }
+  return false;
+}
+
 display::Display HeadlessScreen::GetDisplayNearestWindow(
     gfx::NativeWindow window) const {
   return display_;