Refactor screen/monitor so that gfx::Screen returns monitor object.

ui/gfx/screen_android.cc

Index: ui/gfx/screen_android.cc
diff --git a/ui/gfx/screen_android.cc b/ui/gfx/screen_android.cc
index 27a60c16a7229a9a0b5bba881de28d4c9c5b2a8b..d4eb4916f0c79f4465ca61c96a23ced45c802a06 100644
--- a/ui/gfx/screen_android.cc
+++ b/ui/gfx/screen_android.cc
@@ -5,13 +5,14 @@
 #include "ui/gfx/screen.h"
 
 #include "base/logging.h"
+#include "ui/gfx/monitor.h"
 
 namespace gfx {
 
 // static
-gfx::Size Screen::GetPrimaryMonitorSize() {
+gfx::Monitor Screen::GetPrimaryMonitor() {
   NOTIMPLEMENTED() << "crbug.com/117839 tracks implementation";
-  return gfx::Size(1, 1);
+  return gfx::Monitor(gfx::Rect(0, 0, 1, 1));
 }
 
 // static