Add CHECK's to debug QuicStreamSequencerBuffer in weird state. Add a destruction indicator to detec…

net/quic/core/quic_stream_sequencer_buffer_test.cc

 // Copyright (c) 2015 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/quic/core/quic_stream_sequencer_buffer.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <string>
 #include <utility>
@@ skipping 314 matching lines @@
   LOG(ERROR) << error_details_;
   EXPECT_EQ(100u, read);
   EXPECT_EQ(100u, buffer_->BytesConsumed());
   EXPECT_EQ(source, string(dest, read));
   EXPECT_EQ(1u, helper_->frame_arrival_time_map()->size());
   // The first block should be released as its data has been read out.
   EXPECT_EQ(nullptr, helper_->GetBlock(0));
   EXPECT_TRUE(helper_->CheckBufferInvariants());
 }
 
-TEST_F(QuicStreamSequencerBufferTest, ReadvError) {
-  string source = string(100, 'b');
-  clock_.AdvanceTime(QuicTime::Delta::FromSeconds(1));
-  QuicTime t1 = clock_.ApproximateNow();
-  // Write something into [0, 100).
-  size_t written;
-  buffer_->OnStreamData(0, source, t1, &written, &error_details_);
-  EXPECT_TRUE(helper_->GetBlock(0) != nullptr);
-  EXPECT_TRUE(buffer_->HasBytesToRead());
-  // Read into a iovec array with total capacity of 120 bytes.
-  iovec iov{nullptr, 120};
-  size_t read;
-  EXPECT_EQ(QUIC_STREAM_SEQUENCER_INVALID_STATE,
-            buffer_->Readv(&iov, 1, &read, &error_details_));
-  EXPECT_EQ(0u,
-            error_details_.find(
-                "QuicStreamSequencerBuffer error: Readv() dest == nullptr: true"
-                " blocks_[0] == nullptr: false"));
-}
-
 TEST_F(QuicStreamSequencerBufferTest, ReadvAcrossBlocks) {
   string source(kBlockSizeBytes + 50, 'a');
   // Write 1st block to full and extand 50 bytes to next block.
   size_t written;
   buffer_->OnStreamData(0, source, clock_.ApproximateNow(), &written,
                         &error_details_);
   EXPECT_EQ(source.size(), helper_->ReadableBytes());
   // Iteratively read 512 bytes from buffer_-> Overwrite dest[] each time.
   char dest[512];
   while (helper_->ReadableBytes()) {
@@ skipping 683 matching lines @@
   EXPECT_LE(bytes_to_buffer_, total_bytes_read_) << "iterations: "
                                                  << iterations;
   EXPECT_LE(bytes_to_buffer_, total_bytes_written_);
 }
 
 }  // anonymous namespace
 
 }  // namespace test
 
 }  // namespace net