[MD Settings][People] Fixes take picture button disappearing on page refresh

chrome/browser/ui/webui/settings/chromeos/change_picture_handler.cc

Index: chrome/browser/ui/webui/settings/chromeos/change_picture_handler.cc
diff --git a/chrome/browser/ui/webui/settings/chromeos/change_picture_handler.cc b/chrome/browser/ui/webui/settings/chromeos/change_picture_handler.cc
index f83a8b2a6e546a2f56d090642e279be67872d2f2..6a668cceebe439f1e7094de8be03ab1256e63775 100644
--- a/chrome/browser/ui/webui/settings/chromeos/change_picture_handler.cc
+++ b/chrome/browser/ui/webui/settings/chromeos/change_picture_handler.cc
@@ -205,8 +205,13 @@ void ChangePictureHandler::HandlePageInitialized(const base::ListValue* args) {
   AllowJavascript();
 
   CameraPresenceNotifier* camera = CameraPresenceNotifier::GetInstance();
-  if (!camera_observer_.IsObserving(camera))
-    camera_observer_.Add(camera);
+  if (camera_observer_.IsObserving(camera)) {
+    // If already observing CameraPresenceNotifier (can happen when refreshing
+    // the page), we need to stop observing it, then re-observe it so that
+    // ChangePictureHandler::OnCameraPresenceCheckDone() gets called again.
+    camera_observer_.Remove(camera);
+  }
+  camera_observer_.Add(camera);
 
   SendDefaultImages();
   SendSelectedImage();