Fix net::FileStream to handle POSIX errors correctly.

net/base/file_stream_unittest.cc

Index: net/base/file_stream_unittest.cc
diff --git a/net/base/file_stream_unittest.cc b/net/base/file_stream_unittest.cc
index 17579188d026c841dc0ed4400e3b876c12169945..1f79747fb5ebf97b2f648761d85e6619df21f423 100644
--- a/net/base/file_stream_unittest.cc
+++ b/net/base/file_stream_unittest.cc
@@ -1031,6 +1031,44 @@ TEST_F(FileStreamTest, AsyncOpenAndDelete) {
   EXPECT_FALSE(open_callback.have_result());
 }
 
+// Verify that async Write() errors are mapped correctly.
+TEST_F(FileStreamTest, AsyncWriteError) {
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
+  int flags = base::PLATFORM_FILE_CREATE_ALWAYS |
+              base::PLATFORM_FILE_WRITE |
+              base::PLATFORM_FILE_ASYNC;
+  int rv = stream->OpenSync(temp_file_path(), flags);
+  EXPECT_EQ(OK, rv);
+
+  TestCompletionCallback callback;
+
+  // Try passing NULL buffer to Write() and check that it fails.
+  scoped_refptr<IOBuffer> buf = new WrappedIOBuffer(NULL);
+  rv = stream->Write(buf, 1, callback.callback());
+  if (rv == ERR_IO_PENDING)
+    rv = callback.WaitForResult();
+  EXPECT_LT(rv, 0);
+}
+
+// Verify that async Read() errors are mapped correctly.
+TEST_F(FileStreamTest, AsyncReadError) {
+  scoped_ptr<FileStream> stream(new FileStream(NULL));
+  int flags = base::PLATFORM_FILE_OPEN |
+              base::PLATFORM_FILE_READ |
+              base::PLATFORM_FILE_ASYNC;
+  int rv = stream->OpenSync(temp_file_path(), flags);
+  EXPECT_EQ(OK, rv);
+
+  TestCompletionCallback callback;
+
+  // Try passing NULL buffer to Read() and check that it fails.
+  scoped_refptr<IOBuffer> buf = new WrappedIOBuffer(NULL);
+  rv = stream->Read(buf, 1, callback.callback());
+  if (rv == ERR_IO_PENDING)
+    rv = callback.WaitForResult();
+  EXPECT_LT(rv, 0);
+}
+
 }  // namespace
 
 }  // namespace net