[net] Subtract timestamps to determine if uploading file changed.

net/base/upload_file_element_reader_unittest.cc

 // Copyright (c) 2012 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 "net/base/upload_file_element_reader.h"
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/run_loop.h"
@@ skipping 192 matching lines @@
   EXPECT_EQ(expected, buf);
 }
 
 TEST_F(UploadFileElementReaderTest, FileChanged) {
   base::File::Info info;
   ASSERT_TRUE(base::GetFileInfo(temp_file_path_, &info));
 
   // Expect one second before the actual modification time to simulate change.
   const base::Time expected_modification_time =
       info.last_modified - base::TimeDelta::FromSeconds(1);
-  reader_.reset(
-      new UploadFileElementReader(base::MessageLoopProxy::current().get(),
-                                  temp_file_path_,
-                                  0,
-                                  kuint64max,
-                                  expected_modification_time));
+  reader_.reset(new UploadFileElementReader(
+      base::MessageLoopProxy::current().get(), temp_file_path_, 0, kuint64max,
+      expected_modification_time));
   TestCompletionCallback init_callback;
   ASSERT_EQ(ERR_IO_PENDING, reader_->Init(init_callback.callback()));
   EXPECT_EQ(ERR_UPLOAD_FILE_CHANGED, init_callback.WaitForResult());
 }
 
+TEST_F(UploadFileElementReaderTest, InexactExpectedTimeStamp) {
+  base::File::Info info;
+  ASSERT_TRUE(base::GetFileInfo(temp_file_path_, &info));
+
+  const base::Time expected_modification_time =
+      info.last_modified - base::TimeDelta::FromMilliseconds(900);
+  reader_.reset(new UploadFileElementReader(
+      base::MessageLoopProxy::current().get(), temp_file_path_, 0, kuint64max,
+      expected_modification_time));
+  TestCompletionCallback init_callback;
+  ASSERT_EQ(ERR_IO_PENDING, reader_->Init(init_callback.callback()));
+  EXPECT_EQ(OK, init_callback.WaitForResult());
+}
+
 TEST_F(UploadFileElementReaderTest, WrongPath) {
   const base::FilePath wrong_path(FILE_PATH_LITERAL("wrong_path"));
   reader_.reset(
       new UploadFileElementReader(base::MessageLoopProxy::current().get(),
-                                  wrong_path,
-                                  0,
-                                  kuint64max,
-                                  base::Time()));
+                                  wrong_path, 0, kuint64max, base::Time()));
   TestCompletionCallback init_callback;
   ASSERT_EQ(ERR_IO_PENDING, reader_->Init(init_callback.callback()));
   EXPECT_EQ(ERR_FILE_NOT_FOUND, init_callback.WaitForResult());
 }
 
 }  // namespace net