[fsp] Enable the File System Provider API for extensions.

chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_apitest.cc

Index: chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_apitest.cc
diff --git a/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_apitest.cc b/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_apitest.cc
index a7381e451aa573b981414b162534f99ad597c00d..717fa3d1af36f2a46952052b165b31e77ac6f8a9 100644
--- a/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_apitest.cc
+++ b/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_apitest.cc
@@ -120,4 +120,10 @@ IN_PROC_BROWSER_TEST_F(FileSystemProviderApiTest, WriteFile) {
       << message_;
 }
 
+IN_PROC_BROWSER_TEST_F(FileSystemProviderApiTest, Extension) {
+  ASSERT_TRUE(RunPlatformAppTestWithFlags("file_system_provider/extension",
+                                          kFlagLoadAsComponent))
+      << message_;
+}
+
 }  // namespace extensions