oblivious_http:Update comments to indicate that Client & Gateway are thread-safe.

Additional Context : Adding this as per @ericorth's suggestions on cl/479424618 comments section (Apologies for not linking the actual comment here, as Critique is not giving us a link to that comment)

PiperOrigin-RevId: 481960460
diff --git a/build/source_list.bzl b/build/source_list.bzl
index 110f0da..afc80c7 100644
--- a/build/source_list.bzl
+++ b/build/source_list.bzl
@@ -1093,6 +1093,12 @@
     "http2/test_tools/http2_frame_builder_test.cc",
     "http2/test_tools/http2_random_test.cc",
     "http2/test_tools/random_decoder_test_base_test.cc",
+    "oblivious_http/buffers/oblivious_http_integration_test.cc",
+    "oblivious_http/buffers/oblivious_http_request_test.cc",
+    "oblivious_http/buffers/oblivious_http_response_test.cc",
+    "oblivious_http/common/oblivious_http_header_key_config_test.cc",
+    "oblivious_http/oblivious_http_client_test.cc",
+    "oblivious_http/oblivious_http_gateway_test.cc",
     "quic/core/congestion_control/bandwidth_sampler_test.cc",
     "quic/core/congestion_control/bbr2_simulator_test.cc",
     "quic/core/congestion_control/bbr_sender_test.cc",
@@ -1438,6 +1444,20 @@
 binary_http_srcs = [
     "binary_http/binary_http_message.cc",
 ]
+oblivious_http_hdrs = [
+    "oblivious_http/buffers/oblivious_http_request.h",
+    "oblivious_http/buffers/oblivious_http_response.h",
+    "oblivious_http/common/oblivious_http_header_key_config.h",
+    "oblivious_http/oblivious_http_client.h",
+    "oblivious_http/oblivious_http_gateway.h",
+]
+oblivious_http_srcs = [
+    "oblivious_http/buffers/oblivious_http_request.cc",
+    "oblivious_http/buffers/oblivious_http_response.cc",
+    "oblivious_http/common/oblivious_http_header_key_config.cc",
+    "oblivious_http/oblivious_http_client.cc",
+    "oblivious_http/oblivious_http_gateway.cc",
+]
 qbone_hdrs = [
     "quic/qbone/bonnet/icmp_reachable.h",
     "quic/qbone/bonnet/icmp_reachable_interface.h",
diff --git a/build/source_list.gni b/build/source_list.gni
index 94401df..53814a2 100644
--- a/build/source_list.gni
+++ b/build/source_list.gni
@@ -1093,6 +1093,12 @@
     "src/quiche/http2/test_tools/http2_frame_builder_test.cc",
     "src/quiche/http2/test_tools/http2_random_test.cc",
     "src/quiche/http2/test_tools/random_decoder_test_base_test.cc",
+    "src/quiche/oblivious_http/buffers/oblivious_http_integration_test.cc",
+    "src/quiche/oblivious_http/buffers/oblivious_http_request_test.cc",
+    "src/quiche/oblivious_http/buffers/oblivious_http_response_test.cc",
+    "src/quiche/oblivious_http/common/oblivious_http_header_key_config_test.cc",
+    "src/quiche/oblivious_http/oblivious_http_client_test.cc",
+    "src/quiche/oblivious_http/oblivious_http_gateway_test.cc",
     "src/quiche/quic/core/congestion_control/bandwidth_sampler_test.cc",
     "src/quiche/quic/core/congestion_control/bbr2_simulator_test.cc",
     "src/quiche/quic/core/congestion_control/bbr_sender_test.cc",
@@ -1438,6 +1444,20 @@
 binary_http_srcs = [
     "src/quiche/binary_http/binary_http_message.cc",
 ]
+oblivious_http_hdrs = [
+    "src/quiche/oblivious_http/buffers/oblivious_http_request.h",
+    "src/quiche/oblivious_http/buffers/oblivious_http_response.h",
+    "src/quiche/oblivious_http/common/oblivious_http_header_key_config.h",
+    "src/quiche/oblivious_http/oblivious_http_client.h",
+    "src/quiche/oblivious_http/oblivious_http_gateway.h",
+]
+oblivious_http_srcs = [
+    "src/quiche/oblivious_http/buffers/oblivious_http_request.cc",
+    "src/quiche/oblivious_http/buffers/oblivious_http_response.cc",
+    "src/quiche/oblivious_http/common/oblivious_http_header_key_config.cc",
+    "src/quiche/oblivious_http/oblivious_http_client.cc",
+    "src/quiche/oblivious_http/oblivious_http_gateway.cc",
+]
 qbone_hdrs = [
     "src/quiche/quic/qbone/bonnet/icmp_reachable.h",
     "src/quiche/quic/qbone/bonnet/icmp_reachable_interface.h",
diff --git a/build/source_list.json b/build/source_list.json
index 599ccdd..a877e81 100644
--- a/build/source_list.json
+++ b/build/source_list.json
@@ -1092,6 +1092,12 @@
     "quiche/http2/test_tools/http2_frame_builder_test.cc",
     "quiche/http2/test_tools/http2_random_test.cc",
     "quiche/http2/test_tools/random_decoder_test_base_test.cc",
+    "quiche/oblivious_http/buffers/oblivious_http_integration_test.cc",
+    "quiche/oblivious_http/buffers/oblivious_http_request_test.cc",
+    "quiche/oblivious_http/buffers/oblivious_http_response_test.cc",
+    "quiche/oblivious_http/common/oblivious_http_header_key_config_test.cc",
+    "quiche/oblivious_http/oblivious_http_client_test.cc",
+    "quiche/oblivious_http/oblivious_http_gateway_test.cc",
     "quiche/quic/core/congestion_control/bandwidth_sampler_test.cc",
     "quiche/quic/core/congestion_control/bbr2_simulator_test.cc",
     "quiche/quic/core/congestion_control/bbr_sender_test.cc",
@@ -1437,6 +1443,20 @@
   "binary_http_srcs": [
     "quiche/binary_http/binary_http_message.cc"
   ],
+  "oblivious_http_hdrs": [
+    "quiche/oblivious_http/buffers/oblivious_http_request.h",
+    "quiche/oblivious_http/buffers/oblivious_http_response.h",
+    "quiche/oblivious_http/common/oblivious_http_header_key_config.h",
+    "quiche/oblivious_http/oblivious_http_client.h",
+    "quiche/oblivious_http/oblivious_http_gateway.h"
+  ],
+  "oblivious_http_srcs": [
+    "quiche/oblivious_http/buffers/oblivious_http_request.cc",
+    "quiche/oblivious_http/buffers/oblivious_http_response.cc",
+    "quiche/oblivious_http/common/oblivious_http_header_key_config.cc",
+    "quiche/oblivious_http/oblivious_http_client.cc",
+    "quiche/oblivious_http/oblivious_http_gateway.cc"
+  ],
   "qbone_hdrs": [
     "quiche/quic/qbone/bonnet/icmp_reachable.h",
     "quiche/quic/qbone/bonnet/icmp_reachable_interface.h",