Fix app_shell shutdown crash due to BrowserContextKeyedServices

chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc

Index: chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
diff --git a/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc b/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
index f06038c2df7e7a9524c4af38f7d1cf1f60538969..cf5d75972a3a4ffcad4a75da0fd54d7c41872834 100644
--- a/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
+++ b/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
@@ -291,6 +291,11 @@ class DriveFileSystemExtensionApiTest : public FileSystemExtensionApiTestBase {
   DriveFileSystemExtensionApiTest() : fake_drive_service_(NULL) {}
   virtual ~DriveFileSystemExtensionApiTest() {}
 
+  virtual void TearDown() OVERRIDE {
+    FileSystemExtensionApiTestBase::TearDown();
+    drive::DriveIntegrationServiceFactory::SetFactoryForTest(NULL);
+  }
+
   // FileSystemExtensionApiTestBase OVERRIDE.
   virtual void InitTestFileSystem() OVERRIDE {
     // Set up cache root to be used by DriveIntegrationService. This has to be
@@ -298,10 +303,11 @@ class DriveFileSystemExtensionApiTest : public FileSystemExtensionApiTestBase {
     // initialized by EventRouter.
     ASSERT_TRUE(test_cache_root_.CreateUniqueTempDir());
 
+    create_drive_integration_service_ = base::Bind(
+        &DriveFileSystemExtensionApiTest::CreateDriveIntegrationService,
+        base::Unretained(this));
     drive::DriveIntegrationServiceFactory::SetFactoryForTest(
-        base::Bind(
-            &DriveFileSystemExtensionApiTest::CreateDriveIntegrationService,
-            base::Unretained(this)));
+        &create_drive_integration_service_);
   }
 
   // FileSystemExtensionApiTestBase OVERRIDE.
@@ -326,6 +332,8 @@ class DriveFileSystemExtensionApiTest : public FileSystemExtensionApiTestBase {
 
   base::ScopedTempDir test_cache_root_;
   drive::FakeDriveService* fake_drive_service_;
+  drive::DriveIntegrationServiceFactory::FactoryCallback
+      create_drive_integration_service_;
 };
 
 //