Media Galleries API: Fix MediaGalleriesPreferences finders race.

chrome/browser/media_galleries/media_galleries_dialog_controller.cc

Index: chrome/browser/media_galleries/media_galleries_dialog_controller.cc
diff --git a/chrome/browser/media_galleries/media_galleries_dialog_controller.cc b/chrome/browser/media_galleries/media_galleries_dialog_controller.cc
index c389f65b13f0e75f254d8343501af4e3ed5164c0..fcfd4ebd98b9034bde2c1b8878269c84a80cc738 100644
--- a/chrome/browser/media_galleries/media_galleries_dialog_controller.cc
+++ b/chrome/browser/media_galleries/media_galleries_dialog_controller.cc
@@ -50,19 +50,18 @@ MediaGalleriesDialogController::MediaGalleriesDialogController(
       : web_contents_(web_contents),
         extension_(&extension),
         on_finish_(on_finish) {
+  preferences_ =
+      g_browser_process->media_file_system_registry()->GetPreferences(
+          Profile::FromBrowserContext(web_contents_->GetBrowserContext()));
   // Passing unretained pointer is safe, since the dialog controller
   // is self-deleting, and so won't be deleted until it can be shown
   // and then closed.
-  StorageMonitor::GetInstance()->EnsureInitialized(base::Bind(
-      &MediaGalleriesDialogController::OnStorageMonitorInitialized,
-      base::Unretained(this)));
+  preferences_->EnsureInitialized(
+      base::Bind(&MediaGalleriesDialogController::OnPreferencesInitialized,
+                 base::Unretained(this)));
 }
 
-void MediaGalleriesDialogController::OnStorageMonitorInitialized() {
-  MediaFileSystemRegistry* registry =
-      g_browser_process->media_file_system_registry();
-  preferences_ = registry->GetPreferences(
-      Profile::FromBrowserContext(web_contents_->GetBrowserContext()));
+void MediaGalleriesDialogController::OnPreferencesInitialized() {
   InitializePermissions();
 
   dialog_.reset(MediaGalleriesDialog::Create(this));