Adding `browsing_data_filesystem_helper*` as the first step towards content settings UI.

chrome/test/testing_profile.h

Index: chrome/test/testing_profile.h
diff --git a/chrome/test/testing_profile.h b/chrome/test/testing_profile.h
index 18f925ad640c78a3e500cdfb1c057d75be9389a6..4614c8afeb67d160f7af30cc5b34207ca9dfa909 100644
--- a/chrome/test/testing_profile.h
+++ b/chrome/test/testing_profile.h
@@ -382,6 +382,9 @@ class TestingProfile : public Profile {
   scoped_refptr<ExtensionSpecialStoragePolicy>
       extension_special_storage_policy_;
 
+  // FileSystemContext.  Created lazily by GetFileSystemContext().
+  scoped_refptr<fileapi::FileSystemContext> file_system_context_;
+
   // The proxy prefs tracker.
   scoped_refptr<PrefProxyConfigTracker> pref_proxy_config_tracker_;