Support device scale factor test with popups in LayoutTest

content/shell/browser/blink_test_controller.cc

Index: content/shell/browser/blink_test_controller.cc
diff --git a/content/shell/browser/blink_test_controller.cc b/content/shell/browser/blink_test_controller.cc
index 7b55670058ae32bf91f4c5ad6ffb647b9f2ec954..c34a71663a15c22b8eda1df3ecdf19bf3cd93199 100644
--- a/content/shell/browser/blink_test_controller.cc
+++ b/content/shell/browser/blink_test_controller.cc
@@ -413,6 +413,8 @@ bool BlinkTestController::OnMessageReceived(const IPC::Message& message) {
                         OnGetBluetoothManualChooserEvents)
     IPC_MESSAGE_HANDLER(ShellViewHostMsg_SendBluetoothManualChooserEvent,
                         OnSendBluetoothManualChooserEvent)
+    IPC_MESSAGE_HANDLER(ShellViewHostMsg_SetDeviceScaleFactor,
+                        OnSetDeviceScaleFactor)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -772,4 +774,8 @@ void BlinkTestController::OnSendBluetoothManualChooserEvent(
   bluetooth_chooser_factory_->SendEvent(event, argument);
 }
 
+void BlinkTestController::OnSetDeviceScaleFactor(float scale) {
+  main_window_->SetDeviceScaleFactor(scale);
+}
+
 }  // namespace content