Fix test on Windows

Author: gspencergoog

shell/common/shell_test.cc

@@ -109,6 +109,8 @@ void ShellTest::VSyncFlush(Shell* shell, bool& will_draw_new_frame) {
 void ShellTest::SetViewportMetrics(Shell* shell, double width, double height) {
   flutter::ViewportMetrics viewport_metrics = {
       1,       // device pixel ratio
+      0,       // physical left
+      0,       // physical top
       width,   // physical width
       height,  // physical height
       0,       // padding top