Move chrome.fileSystem implementation to //extensions

chrome/browser/extensions/api/file_system/file_system_apitest.cc

Index: chrome/browser/extensions/api/file_system/file_system_apitest.cc
diff --git a/chrome/browser/extensions/api/file_system/file_system_apitest.cc b/chrome/browser/extensions/api/file_system/file_system_apitest.cc
index 19dd525cbc24ecbcde1d002a4f46544ead2a29cf..15b9989bb89dc7499d0fe22d68c9f68d93c74435 100644
--- a/chrome/browser/extensions/api/file_system/file_system_apitest.cc
+++ b/chrome/browser/extensions/api/file_system/file_system_apitest.cc
@@ -10,13 +10,15 @@
 #include "base/threading/thread_restrictions.h"
 #include "build/build_config.h"
 #include "chrome/browser/apps/app_browsertest_util.h"
-#include "chrome/browser/extensions/api/file_system/file_system_api.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_paths.h"
+#include "extensions/browser/api/file_system/file_system_api.h"
 #include "extensions/browser/extension_prefs.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_registry_observer.h"
 
+// TODO(michaelpg): Port these tests to app_shell: crbug.com/505926.
+
 namespace content {
 class BrowserContext;
 }