Enable HTTP/2 to use a LIFO scheduler to schedule write.

net/spdy/core/lifo_write_scheduler_test.cc

 // Copyright (c) 2017 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/spdy/core/lifo_write_scheduler.h"
 
 #include "net/spdy/core/spdy_protocol.h"
 #include "net/spdy/core/spdy_test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 43 matching lines @@
   lifo.MarkStreamReady(9, true);
   lifo.MarkStreamReady(15, true);
   lifo.MarkStreamReady(7, true);
   lifo.MarkStreamReady(13, true);
   lifo.MarkStreamReady(11, true);
   lifo.MarkStreamReady(3, true);
   lifo.MarkStreamReady(17, true);
   EXPECT_TRUE(lifo.HasReadyStreams());
   EXPECT_EQ((uint32_t)7, lifo.NumReadyStreams());
 
-  EXPECT_SPDY_BUG(lifo.MarkStreamReady(11, true),
-                  "Stream already exists in the list");
-  EXPECT_SPDY_BUG(lifo.MarkStreamNotReady(5),
-                  "Try to remove a stream that is not on list");
-  EXPECT_SPDY_BUG(lifo.MarkStreamNotReady(21),
-                  "Try to remove a stream that is not on list");
+  // Verify MarkStream(Not)Ready() can be called multiple times for the same
+  // stream.
+  lifo.MarkStreamReady(11, true);
+  lifo.MarkStreamNotReady(5);
+  lifo.MarkStreamNotReady(21);
 
   EXPECT_EQ((uint32_t)17, lifo.PopNextReadyStream());
   EXPECT_EQ((uint32_t)15, std::get<0>(lifo.PopNextReadyStreamAndPrecedence()));
   EXPECT_TRUE(lifo.ShouldYield(9));
   EXPECT_FALSE(lifo.ShouldYield(13));
   EXPECT_FALSE(lifo.ShouldYield(15));
 
   lifo.MarkStreamNotReady(3);
   EXPECT_TRUE(peer.GetReadyList()->find(3) == peer.GetReadyList()->end());
   lifo.MarkStreamNotReady(13);
   EXPECT_TRUE(peer.GetReadyList()->find(13) == peer.GetReadyList()->end());
   lifo.MarkStreamNotReady(7);
   EXPECT_TRUE(peer.GetReadyList()->find(7) == peer.GetReadyList()->end());
   EXPECT_EQ((uint32_t)2, lifo.NumReadyStreams());
+
+  lifo.MarkStreamNotReady(9);
+  lifo.MarkStreamNotReady(11);
+  EXPECT_FALSE(lifo.ShouldYield(1));
 }
 
 // Test add and remove from registered list.
 TEST(LifoWriteSchedulerTest, RegisterListTest) {
   LifoWriteScheduler<SpdyStreamId> lifo;
   LifoWriteSchedulerPeer<SpdyStreamId> peer(&lifo);
   SpdyStreamPrecedence precedence(1);
   lifo.RegisterStream(3, precedence);
   lifo.RegisterStream(5, precedence);
   lifo.RegisterStream(7, precedence);
@@ skipping 43 matching lines @@
   EXPECT_EQ(3, lifo.GetLatestEventWithPrecedence(5));
   EXPECT_EQ(4, lifo.GetLatestEventWithPrecedence(3));
   EXPECT_EQ(8, lifo.GetLatestEventWithPrecedence(1));
   EXPECT_SPDY_BUG(lifo.GetLatestEventWithPrecedence(11),
                   "Stream 11 is not registered");
 }
 
 }  // namespace test
 
 }  // namespace net