Prepare /storage/browser/fileapi for TestCompletionCallback with non-repeating callbacks

Make sure that we don't re-use the callbacks from TestCompletionCallback,
so that we're prepared for when they become non-repeating callbacks (i.e.
base::CompletionOnceCallback), instead of base::CompletionCallback.

This CL was uploaded by git cl split.

TBR=tzik@chromium.org

Bug: 807724
Change-Id: Id1ce48998eeda76b142fc0ec91de903a47411344
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1541113
Commit-Queue: Mario Sanchez Prada <mario@igalia.com>
Reviewed-by: Bence Béky <bnc@chromium.org>
Auto-Submit: Mario Sanchez Prada <mario@igalia.com>
Cr-Commit-Position: refs/heads/master@{#645230}

storage/browser/fileapi/file_stream_reader_test_utils.cc

@@ -21,11 +21,11 @@ void ReadFromReader(FileStreamReader* reader,
   ASSERT_TRUE(reader != nullptr);
   ASSERT_TRUE(result != nullptr);
   *result = net::OK;
-  net::TestCompletionCallback callback;
   size_t total_bytes_read = 0;
   while (total_bytes_read < size) {
     scoped_refptr<net::IOBufferWithSize> buf(
         base::MakeRefCounted<net::IOBufferWithSize>(size - total_bytes_read));
+    net::TestCompletionCallback callback;
     int rv = reader->Read(buf.get(), buf->size(), callback.callback());
     if (rv == net::ERR_IO_PENDING)
       rv = callback.WaitForResult();

storage/browser/fileapi/file_system_file_stream_reader_unittest.cc

@@ -169,17 +169,18 @@ TEST_F(FileSystemFileStreamReaderTest, GetLengthAfterModified) {
 
   std::unique_ptr<FileSystemFileStreamReader> reader(
       CreateFileReader(kTestFileName, 0, fake_expected_modification_time));
-  net::TestInt64CompletionCallback callback;
-  int64_t result = reader->GetLength(callback.callback());
+  net::TestInt64CompletionCallback callback1;
+  int64_t result = reader->GetLength(callback1.callback());
   if (result == net::ERR_IO_PENDING)
-    result = callback.WaitForResult();
+    result = callback1.WaitForResult();
   ASSERT_EQ(net::ERR_UPLOAD_FILE_CHANGED, result);
 
   // With nullptr expected modification time this should work.
   reader.reset(CreateFileReader(kTestFileName, 0, base::Time()));
-  result = reader->GetLength(callback.callback());
+  net::TestInt64CompletionCallback callback2;
+  result = reader->GetLength(callback2.callback());
   if (result == net::ERR_IO_PENDING)
-    result = callback.WaitForResult();
+    result = callback2.WaitForResult();
   ASSERT_EQ(kTestDataSize, result);
 }
 

storage/browser/fileapi/file_writer_impl_unittest.cc

@@ -86,10 +86,10 @@ class FileWriterImplTest : public testing::Test {
     std::unique_ptr<FileStreamReader> reader =
         file_system_context_->CreateFileStreamReader(
             url, 0, std::numeric_limits<int64_t>::max(), base::Time());
-    net::TestCompletionCallback callback;
     std::string result;
     while (true) {
       auto buf = base::MakeRefCounted<net::IOBufferWithSize>(4096);
+      net::TestCompletionCallback callback;
       int rv = reader->Read(buf.get(), buf->size(), callback.callback());
       if (rv == net::ERR_IO_PENDING)
         rv = callback.WaitForResult();

storage/browser/fileapi/local_file_stream_reader_unittest.cc

@@ -160,17 +160,18 @@ TEST_F(LocalFileStreamReaderTest, GetLengthAfterModified) {
 
   std::unique_ptr<LocalFileStreamReader> reader(
       CreateFileReader(test_path(), 0, test_file_modification_time()));
-  net::TestInt64CompletionCallback callback;
-  int64_t result = reader->GetLength(callback.callback());
+  net::TestInt64CompletionCallback callback1;
+  int64_t result = reader->GetLength(callback1.callback());
   if (result == net::ERR_IO_PENDING)
-    result = callback.WaitForResult();
+    result = callback1.WaitForResult();
   ASSERT_EQ(net::ERR_UPLOAD_FILE_CHANGED, result);
 
   // With nullptr expected modification time this should work.
   reader.reset(CreateFileReader(test_path(), 0, base::Time()));
-  result = reader->GetLength(callback.callback());
+  net::TestInt64CompletionCallback callback2;
+  result = reader->GetLength(callback2.callback());
   if (result == net::ERR_IO_PENDING)
-    result = callback.WaitForResult();
+    result = callback2.WaitForResult();
   ASSERT_EQ(kTestDataSize, result);
 }