mediaview: Hack to avoid Files app to freeze soon after login.

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root_unittest.cc

Index: chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root_unittest.cc
diff --git a/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root_unittest.cc b/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root_unittest.cc
index df9f467a297502cc77c426fed74d69de636d8d30..6c62db36ea2965c1801a85be3416c48f5db419ee 100644
--- a/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root_unittest.cc
+++ b/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root_unittest.cc
@@ -315,6 +315,14 @@ TEST_F(ArcDocumentsProviderRootTest, WatchChanged) {
     run_loop.Run();
   }
 
+  // Even if AddWatcher() returns, the watch may not have started. In order to
+  // make installation finish we run the message loop until idle. This depends
+  // on the behavior of FakeFileSystemInstance.
+  //
+  // TODO(crbug.com/698624): Remove the hack to make AddWatcher() return
+  // immediately.
+  base::RunLoop().RunUntilIdle();
+
   EXPECT_EQ(0, num_called);
   fake_file_system_.TriggerWatchers(kAuthority, kDirSpec.document_id,
                                     mojom::ChangeType::CHANGED);
@@ -357,6 +365,14 @@ TEST_F(ArcDocumentsProviderRootTest, WatchDeleted) {
     run_loop.Run();
   }
 
+  // Even if AddWatcher() returns, the watch may not have started. In order to
+  // make installation finish we run the message loop until idle. This depends
+  // on the behavior of FakeFileSystemInstance.
+  //
+  // TODO(crbug.com/698624): Remove the hack to make AddWatcher() return
+  // immediately.
+  base::RunLoop().RunUntilIdle();
+
   EXPECT_EQ(0, num_called);
   fake_file_system_.TriggerWatchers(kAuthority, kDirSpec.document_id,
                                     mojom::ChangeType::DELETED);