Add Finch experiment for selectively bypassing proxies.

components/data_reduction_proxy/browser/data_reduction_proxy_protocol.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_PROTOCOL_H_
 #define COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_PROTOCOL_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 
 namespace base {
 class TimeDelta;
 }
 
 namespace net {
 class HttpResponseHeaders;
 class ProxyServer;
 class URLRequest;
+class ProxyInfo;
 }
 
 class GURL;
 
 namespace data_reduction_proxy {
 
 class DataReductionProxyParams;
 
 // Decides whether to mark the data reduction proxy as temporarily bad and
 // put it on the proxy retry list. Returns true if the request should be
 // retried. Sets |override_response_headers| to redirect if so.
 bool MaybeBypassProxyAndPrepareToRetry(
     const DataReductionProxyParams* params,
     net::URLRequest* request,
     const net::HttpResponseHeaders* original_response_headers,
     scoped_refptr<net::HttpResponseHeaders>* override_response_headers);
 
+// Upon ProxyService.ResolveProxy(), bypass if the effective proxy is the data
+// reduction proxy, the net::LOAD_BYPASS_DATA_REDUCTION_PROXY load_flag is
+// set, and the DataCompressionProxyCriticalBypass Finch trial is set.
+void OnResolveProxyHandler(const GURL& url, int load_flags,
+                           net::ProxyInfo* result);
+
 // Returns true if the request method is idempotent. Only idempotent requests
 // are retried on a bypass. Visible as part of the public API for testing.
 bool IsRequestIdempotent(const net::URLRequest* request);
 
 // Sets the override headers to contain a status line that indicates a
 // redirect (a 302), a "Location:" header that points to the request url,
 // and sets load flags to bypass proxies.
 // Visible as part of the public API for testing.
 void OverrideResponseAsRedirect(
     net::URLRequest* request,
     const net::HttpResponseHeaders* original_response_headers,
     scoped_refptr<net::HttpResponseHeaders>* override_response_headers);
 
 // Adds non-empty entries in |data_reduction_proxies| to the retry map
 // maintained by the proxy service of the request. Adds
 // |data_reduction_proxies.second| to the retry list only if |bypass_all| is
 // true. Visible as part of the public API for testing.
 void MarkProxiesAsBadUntil(net::URLRequest* request,
                            base::TimeDelta& bypass_duration,
                            bool bypass_all,
                            const std::pair<GURL, GURL>& data_reduction_proxies);
 
 }  // namespace data_reduction_proxy
 #endif  // COMPONENTS_DATA_REDUCTION_PROXY_BROWSER_DATA_REDUCTION_PROXY_PROTOCOL_H_