Reset HTTP/2 stream on line-folded response headers.

Also add unittests for HeaderCoalescer.

BUG=524041, 621487

Review-Url: https://codereview.chromium.org/2184253002
Cr-Commit-Position: refs/heads/master@{#408962}
diff --git a/net/net.gypi b/net/net.gypi
index 393625d..5967bd9a 100644
--- a/net/net.gypi
+++ b/net/net.gypi
@@ -1778,6 +1778,7 @@
       'spdy/bidirectional_stream_spdy_impl_unittest.cc',
       'spdy/buffered_spdy_framer_unittest.cc',
       'spdy/fuzzing/hpack_fuzz_util_test.cc',
+      'spdy/header_coalescer_test.cc',
       'spdy/hpack/hpack_decoder_test.cc',
       'spdy/hpack/hpack_encoder_test.cc',
       'spdy/hpack/hpack_entry_test.cc',