Return chrome-proxy-ect header code (post M59 branch)

components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
index f232e945e03ec905fc9263f217c6114737cf8c69..3e79f4a6a98b8f89b3cf574a21d12b2d73c861a1 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
@@ -19,6 +19,7 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h"
 #include "components/data_reduction_proxy/core/browser/data_use_group.h"
 #include "components/data_reduction_proxy/core/browser/data_use_group_provider.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_util.h"
 #include "components/data_reduction_proxy/core/common/lofi_decider.h"
@@ -26,6 +27,7 @@
 #include "net/base/mime_util.h"
 #include "net/http/http_request_headers.h"
 #include "net/http/http_response_headers.h"
+#include "net/nqe/effective_connection_type.h"
 #include "net/nqe/network_quality_estimator.h"
 #include "net/proxy/proxy_info.h"
 #include "net/proxy/proxy_server.h"
@@ -136,9 +138,11 @@ void VerifyHttpRequestHeaders(bool via_chrome_proxy,
                               const net::HttpRequestHeaders& headers) {
   if (via_chrome_proxy) {
     DCHECK(headers.HasHeader(chrome_proxy_header()));
+    DCHECK(headers.HasHeader(chrome_proxy_ect_header()));
   } else {
     DCHECK(!headers.HasHeader(chrome_proxy_header()));
     DCHECK(!headers.HasHeader(chrome_proxy_accept_transform_header()));
+    DCHECK(!headers.HasHeader(chrome_proxy_ect_header()));
   }
 }
 
@@ -223,6 +227,8 @@ void DataReductionProxyNetworkDelegate::OnBeforeStartTransactionInternal(
         ->MaybeSetAcceptTransformHeader(
             *request, data_reduction_proxy_config_->lofi_off(), headers);
   }
+
+  MaybeAddChromeProxyECTHeader(headers, *request);
 }
 
 void DataReductionProxyNetworkDelegate::OnBeforeSendHeadersInternal(
@@ -281,6 +287,7 @@ void DataReductionProxyNetworkDelegate::OnBeforeSendHeadersInternal(
       // Chrome-Proxy-Accept-Transform header.
       lofi_decider->RemoveAcceptTransformHeader(headers);
     }
+    RemoveChromeProxyECTHeader(headers);
     VerifyHttpRequestHeaders(false, *headers);
     return;
   }
@@ -574,4 +581,48 @@ void DataReductionProxyNetworkDelegate::MaybeAddBrotliToAcceptEncodingHeader(
                              header_value);
 }
 
+void DataReductionProxyNetworkDelegate::MaybeAddChromeProxyECTHeader(
+    net::HttpRequestHeaders* request_headers,
+    const net::URLRequest& request) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // This method should be called only when the resolved proxy was a data
+  // saver proxy.
+  DCHECK(request.url().is_valid());
+  DCHECK(!request.url().SchemeIsCryptographic());
+  DCHECK(request.url().SchemeIsHTTPOrHTTPS());
+
+  if (request_headers->HasHeader(chrome_proxy_ect_header()))
+    request_headers->RemoveHeader(chrome_proxy_ect_header());
+
+  if (request.context()->network_quality_estimator()) {
+    net::EffectiveConnectionType type = request.context()
+                                            ->network_quality_estimator()
+                                            ->GetEffectiveConnectionType();
+    if (type > net::EFFECTIVE_CONNECTION_TYPE_OFFLINE) {
+      DCHECK_NE(net::EFFECTIVE_CONNECTION_TYPE_LAST, type);
+      request_headers->SetHeader(chrome_proxy_ect_header(),
+                                 net::GetNameForEffectiveConnectionType(type));
+      return;
+    }
+  }
+  request_headers->SetHeader(chrome_proxy_ect_header(),
+                             net::GetNameForEffectiveConnectionType(
+                                 net::EFFECTIVE_CONNECTION_TYPE_UNKNOWN));
+
+  static_assert(net::EFFECTIVE_CONNECTION_TYPE_OFFLINE + 1 ==
+                    net::EFFECTIVE_CONNECTION_TYPE_SLOW_2G,
+                "ECT enum value is not handled.");
+  static_assert(net::EFFECTIVE_CONNECTION_TYPE_4G + 1 ==
+                    net::EFFECTIVE_CONNECTION_TYPE_LAST,
+                "ECT enum value is not handled.");
+}
+
+void DataReductionProxyNetworkDelegate::RemoveChromeProxyECTHeader(
+    net::HttpRequestHeaders* request_headers) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  request_headers->RemoveHeader(chrome_proxy_ect_header());
+}
+
 }  // namespace data_reduction_proxy