Add support for refreshing contents of providers which don't support watchers.

chrome/browser/chromeos/file_system_provider/operations/read_file_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/file_system_provider/operations/read_file.h"
 
 #include <string>
 
 #include "base/files/file.h"
 #include "base/files/file_path.h"
@@ skipping 61 matching lines @@
 }  // namespace
 
 class FileSystemProviderOperationsReadFileTest : public testing::Test {
  protected:
   FileSystemProviderOperationsReadFileTest() {}
   ~FileSystemProviderOperationsReadFileTest() override {}
 
   void SetUp() override {
     file_system_info_ = ProvidedFileSystemInfo(
         kExtensionId, MountOptions(kFileSystemId, "" /* display_name */),
-        base::FilePath(), false /* configurable */, extensions::SOURCE_FILE);
+        base::FilePath(), false /* configurable */, true /* watchable */,
+        extensions::SOURCE_FILE);
     io_buffer_ = make_scoped_refptr(new net::IOBuffer(kOffset + kLength));
   }
 
   ProvidedFileSystemInfo file_system_info_;
   scoped_refptr<net::IOBuffer> io_buffer_;
 };
 
 TEST_F(FileSystemProviderOperationsReadFileTest, Execute) {
   using extensions::api::file_system_provider::ReadFileRequestedOptions;
 
@@ skipping 125 matching lines @@
                     base::File::FILE_ERROR_TOO_MANY_OPENED);
 
   ASSERT_EQ(1u, callback_logger.events().size());
   CallbackLogger::Event* event = callback_logger.events()[0];
   EXPECT_EQ(base::File::FILE_ERROR_TOO_MANY_OPENED, event->result());
 }
 
 }  // namespace operations
 }  // namespace file_system_provider
 }  // namespace chromeos