Add more CHECKs in QuicChromiumClientStream

To investigate a crash.

Bug: 1335423
Change-Id: I6ff013fa16a9a7a47637142f4b732b62b9d6d7b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3755025
Reviewed-by: Nidhi Jaju <nidhijaju@chromium.org>
Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1023044}

net/quic/quic_chromium_client_stream.cc

@@ -99,6 +99,11 @@ void QuicChromiumClientStream::Handle::OnDataAvailable() {
   if (!read_body_callback_)
     return;  // Wait for ReadBody to be called.
 
+  // TODO(https://crbug.com/1335423): Change to DCHECK() or remove after bug is
+  // fixed.
+  CHECK(read_body_buffer_);
+  CHECK_GT(read_body_buffer_len_, 0);
+
   int rv = stream_->Read(read_body_buffer_, read_body_buffer_len_);
   if (rv == ERR_IO_PENDING)
     return;  // Spurrious, likely because of trailers?
@@ -203,6 +208,11 @@ int QuicChromiumClientStream::Handle::ReadBody(
   if (rv != ERR_IO_PENDING)
     return rv;
 
+  // TODO(https://crbug.com/1335423): Change to DCHECK() or remove after bug is
+  // fixed.
+  CHECK(buffer);
+  CHECK_GT(buffer_len, 0);
+
   SetCallback(std::move(callback), &read_body_callback_);
   read_body_buffer_ = buffer;
   read_body_buffer_len_ = buffer_len;