Add Finch experiment for selectively bypassing proxies.

chrome/browser/net/chrome_network_delegate.h

 // Copyright (c) 2012 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 CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_
 #define CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 124 matching lines @@
     data_reduction_proxy_usage_stats_ = usage_stats;
   }
 
   // |data_reduction_proxy_auth_request_handler_| must outlive this
   // ChromeNetworkDelegate.
   void set_data_reduction_proxy_auth_request_handler(
       data_reduction_proxy::DataReductionProxyAuthRequestHandler* handler) {
     data_reduction_proxy_auth_request_handler_ = handler;
   }
 
+  // Provides an opportunity to interpose on proxy resolution. Called before
+  // ProxyService.ResolveProxy() returns. |proxy_info| contains information
+  // about the proxy being used, and may be modified by this callback.
+  typedef base::Callback<void(
+      const GURL& url,
+      int load_flags,
+      const data_reduction_proxy::DataReductionProxyParams* params,
+      net::ProxyInfo* result)> OnResolveProxyHandler;

[mmenke, 2014/07/07 20:21:59]

nit:  Per Google style guide, typedefs (and enums) go first.

[rcs, 2014/07/07 22:08:49]

Done.

+
+  void set_on_resolve_proxy_handler(OnResolveProxyHandler* handler) {
+    on_resolve_proxy_handler_ = handler;
+  }
+
   // Adds the Client Hints header to HTTP requests.
   void SetEnableClientHints();
 
   // Causes |OnCanThrottleRequest| to always return false, for all
   // instances of this object.
   static void NeverThrottleRequests();
 
   // Binds the pref members to |pref_service| and moves them to the IO thread.
   // |enable_referrers| cannot be NULL, the others can.
   // This method should be called on the UI thread.
@@ skipping 16 matching lines @@
   // responsible for deleting the returned value.
   base::Value* SessionNetworkStatsInfoToValue() const;
 
  private:
   friend class ChromeNetworkDelegateTest;
 
   // NetworkDelegate implementation.
   virtual int OnBeforeURLRequest(net::URLRequest* request,
                                  const net::CompletionCallback& callback,
                                  GURL* new_url) OVERRIDE;
+  virtual void OnResolveProxy(
+      const GURL& url, int load_flags, net::ProxyInfo* result) OVERRIDE;
   virtual int OnBeforeSendHeaders(net::URLRequest* request,
                                   const net::CompletionCallback& callback,
                                   net::HttpRequestHeaders* headers) OVERRIDE;
   virtual void OnBeforeSendProxyHeaders(
       net::URLRequest* request,
       const net::ProxyInfo& proxy_info,
       net::HttpRequestHeaders* headers) OVERRIDE;
   virtual void OnSendHeaders(net::URLRequest* request,
                              const net::HttpRequestHeaders& headers) OVERRIDE;
   virtual int OnHeadersReceived(
@@ skipping 82 matching lines @@
 
   // |data_reduction_proxy_params_| must outlive this ChromeNetworkDelegate.
   data_reduction_proxy::DataReductionProxyParams* data_reduction_proxy_params_;
   // |data_reduction_proxy_usage_stats_| must outlive this
   // ChromeNetworkDelegate.
   data_reduction_proxy::DataReductionProxyUsageStats*
       data_reduction_proxy_usage_stats_;
   data_reduction_proxy::DataReductionProxyAuthRequestHandler*
   data_reduction_proxy_auth_request_handler_;
 
+  OnResolveProxyHandler* on_resolve_proxy_handler_;

[mmenke, 2014/07/07 20:21:59]

Suggest not making this a pointer.  Callbacks have a method...is_empty(), I
believe (Or maybe is_null() or is_valid() or somesuch).

As-is, this is perfectly safe, just keeping a pointer to a callback seems a bit
ugly to me.

[rcs, 2014/07/07 22:08:49]

Done.

+
   DISALLOW_COPY_AND_ASSIGN(ChromeNetworkDelegate);
 };
 
 #endif  // CHROME_BROWSER_NET_CHROME_NETWORK_DELEGATE_H_