Move data reduction proxy to Chrome-Proxy header for authentication

net/http/http_transaction.h

Index: net/http/http_transaction.h
diff --git a/net/http/http_transaction.h b/net/http/http_transaction.h
index ed1b20dac2ffb8298c67c5bfc83d4850027b805b..db8ed5211b0d6c1c1c64aa178d7cff02edba0698 100644
--- a/net/http/http_transaction.h
+++ b/net/http/http_transaction.h
@@ -21,6 +21,7 @@ struct HttpRequestInfo;
 class HttpResponseInfo;
 class IOBuffer;
 struct LoadTimingInfo;
+class ProxyInfo;
 class QuicServerInfo;
 class X509Certificate;
 
@@ -33,6 +34,12 @@ class NET_EXPORT_PRIVATE HttpTransaction {
   // ResumeNetworkStart is called before establishing a connection.
   typedef base::Callback<void(bool* defer)> BeforeNetworkStartCallback;
 
+  // Provides an opportunity to add proxy-specific request headers. Called after
+  // it is determined that a proxy is being used and before the request headers
+  // are sent. |proxy_info| contains information about the proxy being used.
+  typedef base::Callback<void(
+      const ProxyInfo& proxy_info)> BeforeProxyHeadersSentCallback;
+
   // Stops any pending IO and destroys the transaction object.
   virtual ~HttpTransaction() {}
 
@@ -158,6 +165,11 @@ class NET_EXPORT_PRIVATE HttpTransaction {
   virtual void SetBeforeNetworkStartCallback(
       const BeforeNetworkStartCallback& callback) = 0;
 
+  // Set the callback to receive notification just before a proxy request
+  // is to be sent.
+  virtual void SetBeforeProxyHeadersSentCallback(
+      const BeforeProxyHeadersSentCallback& callback) = 0;
+
   // Resumes the transaction after being deferred.
   virtual int ResumeNetworkStart() = 0;
 };