Consolidates references to the third-party nghttp2.h header in a single place.

This will simplify maintenance of any platform-specific build fixes.

PiperOrigin-RevId: 410313333
diff --git a/http2/adapter/callback_visitor.cc b/http2/adapter/callback_visitor.cc
index 49a76e7..dcdca64 100644
--- a/http2/adapter/callback_visitor.cc
+++ b/http2/adapter/callback_visitor.cc
@@ -3,7 +3,6 @@
 #include "absl/strings/escaping.h"
 #include "http2/adapter/http2_util.h"
 #include "http2/adapter/nghttp2_util.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 #include "common/quiche_endian.h"
 
 // This visitor implementation needs visibility into the
diff --git a/http2/adapter/callback_visitor.h b/http2/adapter/callback_visitor.h
index 3bef25c..6d1915c 100644
--- a/http2/adapter/callback_visitor.h
+++ b/http2/adapter/callback_visitor.h
@@ -7,8 +7,8 @@
 
 #include "absl/container/flat_hash_map.h"
 #include "http2/adapter/http2_visitor_interface.h"
+#include "http2/adapter/nghttp2.h"
 #include "http2/adapter/nghttp2_util.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 #include "common/platform/api/quiche_export.h"
 
 namespace http2 {
diff --git a/http2/adapter/mock_nghttp2_callbacks.h b/http2/adapter/mock_nghttp2_callbacks.h
index 98acad9..85bc6a9 100644
--- a/http2/adapter/mock_nghttp2_callbacks.h
+++ b/http2/adapter/mock_nghttp2_callbacks.h
@@ -4,8 +4,8 @@
 #include <cstdint>
 
 #include "absl/strings/string_view.h"
+#include "http2/adapter/nghttp2.h"
 #include "http2/adapter/nghttp2_util.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 #include "common/platform/api/quiche_export.h"
 #include "common/platform/api/quiche_test.h"
 
diff --git a/http2/adapter/nghttp2.h b/http2/adapter/nghttp2.h
new file mode 100644
index 0000000..b8487c0
--- /dev/null
+++ b/http2/adapter/nghttp2.h
@@ -0,0 +1,11 @@
+#ifndef QUICHE_HTTP2_ADAPTER_NGHTTP2_H_
+#define QUICHE_HTTP2_ADAPTER_NGHTTP2_H_
+
+#include <cstddef>
+
+// Required to build on Windows.
+using ssize_t = ptrdiff_t;
+
+#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
+
+#endif  // QUICHE_HTTP2_ADAPTER_NGHTTP2_H_
diff --git a/http2/adapter/nghttp2_adapter.cc b/http2/adapter/nghttp2_adapter.cc
index e780562..821eb8c 100644
--- a/http2/adapter/nghttp2_adapter.cc
+++ b/http2/adapter/nghttp2_adapter.cc
@@ -4,9 +4,9 @@
 #include "absl/strings/str_cat.h"
 #include "absl/strings/string_view.h"
 #include "http2/adapter/http2_visitor_interface.h"
+#include "http2/adapter/nghttp2.h"
 #include "http2/adapter/nghttp2_callbacks.h"
 #include "http2/adapter/nghttp2_data_provider.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 #include "common/platform/api/quiche_logging.h"
 #include "common/quiche_endian.h"
 
diff --git a/http2/adapter/nghttp2_adapter_test.cc b/http2/adapter/nghttp2_adapter_test.cc
index 5f958b8..cae2cec 100644
--- a/http2/adapter/nghttp2_adapter_test.cc
+++ b/http2/adapter/nghttp2_adapter_test.cc
@@ -3,11 +3,11 @@
 #include "http2/adapter/http2_protocol.h"
 #include "http2/adapter/http2_visitor_interface.h"
 #include "http2/adapter/mock_http2_visitor.h"
+#include "http2/adapter/nghttp2.h"
 #include "http2/adapter/nghttp2_test_utils.h"
 #include "http2/adapter/oghttp2_util.h"
 #include "http2/adapter/test_frame_sequence.h"
 #include "http2/adapter/test_utils.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 #include "common/platform/api/quiche_test.h"
 
 namespace http2 {
diff --git a/http2/adapter/nghttp2_callbacks.cc b/http2/adapter/nghttp2_callbacks.cc
index 9e04158..2ef6633 100644
--- a/http2/adapter/nghttp2_callbacks.cc
+++ b/http2/adapter/nghttp2_callbacks.cc
@@ -9,7 +9,6 @@
 #include "http2/adapter/http2_visitor_interface.h"
 #include "http2/adapter/nghttp2_data_provider.h"
 #include "http2/adapter/nghttp2_util.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 #include "common/platform/api/quiche_bug_tracker.h"
 #include "common/platform/api/quiche_logging.h"
 #include "common/quiche_endian.h"
diff --git a/http2/adapter/nghttp2_callbacks.h b/http2/adapter/nghttp2_callbacks.h
index 75640ed..293c6d6 100644
--- a/http2/adapter/nghttp2_callbacks.h
+++ b/http2/adapter/nghttp2_callbacks.h
@@ -4,8 +4,8 @@
 #include <cstdint>
 
 #include "http2/adapter/http2_protocol.h"
+#include "http2/adapter/nghttp2.h"
 #include "http2/adapter/nghttp2_util.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 
 namespace http2 {
 namespace adapter {
diff --git a/http2/adapter/nghttp2_data_provider.h b/http2/adapter/nghttp2_data_provider.h
index 9e9119f..9e3601a 100644
--- a/http2/adapter/nghttp2_data_provider.h
+++ b/http2/adapter/nghttp2_data_provider.h
@@ -5,7 +5,7 @@
 #include <memory>
 
 #include "http2/adapter/data_source.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
+#include "http2/adapter/nghttp2.h"
 
 namespace http2 {
 namespace adapter {
diff --git a/http2/adapter/nghttp2_session.h b/http2/adapter/nghttp2_session.h
index f84713f..c5c1b73 100644
--- a/http2/adapter/nghttp2_session.h
+++ b/http2/adapter/nghttp2_session.h
@@ -4,8 +4,8 @@
 #include <cstdint>
 
 #include "http2/adapter/http2_session.h"
+#include "http2/adapter/nghttp2.h"
 #include "http2/adapter/nghttp2_util.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 #include "common/platform/api/quiche_export.h"
 
 namespace http2 {
diff --git a/http2/adapter/nghttp2_test.cc b/http2/adapter/nghttp2_test.cc
index 0b977dc..a65a775 100644
--- a/http2/adapter/nghttp2_test.cc
+++ b/http2/adapter/nghttp2_test.cc
@@ -1,4 +1,4 @@
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
+#include "http2/adapter/nghttp2.h"
 
 #include "absl/strings/str_cat.h"
 #include "http2/adapter/mock_nghttp2_callbacks.h"
diff --git a/http2/adapter/nghttp2_test_utils.h b/http2/adapter/nghttp2_test_utils.h
index abb11dd..92632dc 100644
--- a/http2/adapter/nghttp2_test_utils.h
+++ b/http2/adapter/nghttp2_test_utils.h
@@ -6,7 +6,7 @@
 
 #include "absl/strings/string_view.h"
 #include "http2/adapter/http2_protocol.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
+#include "http2/adapter/nghttp2.h"
 #include "common/platform/api/quiche_export.h"
 #include "common/platform/api/quiche_test.h"
 
diff --git a/http2/adapter/nghttp2_util.cc b/http2/adapter/nghttp2_util.cc
index 2d0171c..3dc87ab 100644
--- a/http2/adapter/nghttp2_util.cc
+++ b/http2/adapter/nghttp2_util.cc
@@ -6,7 +6,6 @@
 #include "absl/strings/string_view.h"
 #include "absl/types/span.h"
 #include "http2/adapter/http2_protocol.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
 #include "common/platform/api/quiche_logging.h"
 #include "common/quiche_endian.h"
 
diff --git a/http2/adapter/nghttp2_util.h b/http2/adapter/nghttp2_util.h
index 57702a3..a24d98d 100644
--- a/http2/adapter/nghttp2_util.h
+++ b/http2/adapter/nghttp2_util.h
@@ -11,7 +11,7 @@
 #include "http2/adapter/data_source.h"
 #include "http2/adapter/http2_protocol.h"
 #include "http2/adapter/http2_visitor_interface.h"
-#include "third_party/nghttp2/src/lib/includes/nghttp2/nghttp2.h"
+#include "http2/adapter/nghttp2.h"
 #include "spdy/core/spdy_header_block.h"
 
 namespace http2 {