Add Finch experiment for selectively bypassing proxies.

net/proxy/proxy_service.cc

Index: net/proxy/proxy_service.cc
diff --git a/net/proxy/proxy_service.cc b/net/proxy/proxy_service.cc
index c5cd6ac3354c6630f64426dd938a29d1a00e7ee3..94eeefda79dcc2d865465d5d5b20cc41a1fb6d21 100644
--- a/net/proxy/proxy_service.cc
+++ b/net/proxy/proxy_service.cc
@@ -19,6 +19,7 @@
 #include "base/thread_task_runner_handle.h"
 #include "base/values.h"
 #include "net/base/completion_callback.h"
+#include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
 #include "net/base/net_log.h"
 #include "net/base/net_util.h"
@@ -734,6 +735,8 @@ class ProxyService::PacRequest
  public:
     PacRequest(ProxyService* service,
                const GURL& url,
+               int load_flags,
+               NetworkDelegate* network_delegate,
                ProxyInfo* results,
                const net::CompletionCallback& user_callback,
                const BoundNetLog& net_log)
@@ -741,6 +744,8 @@ class ProxyService::PacRequest
         user_callback_(user_callback),
         results_(results),
         url_(url),
+        load_flags_(load_flags),
+        network_delegate_(network_delegate),
         resolve_job_(NULL),
         config_id_(ProxyConfig::kInvalidConfigID),
         config_source_(PROXY_CONFIG_SOURCE_UNKNOWN),
@@ -771,7 +776,8 @@ class ProxyService::PacRequest
   }
 
   void StartAndCompleteCheckingForSynchronous() {
-    int rv = service_->TryToCompleteSynchronously(url_, results_);
+    int rv = service_->TryToCompleteSynchronously(url_, load_flags_,
+                                                  network_delegate_, results_);
     if (rv == ERR_IO_PENDING)
       rv = Start();
     if (rv != ERR_IO_PENDING)
@@ -811,7 +817,9 @@ class ProxyService::PacRequest
     DCHECK(!was_cancelled());
 
     // Note that DidFinishResolvingProxy might modify |results_|.
-    int rv = service_->DidFinishResolvingProxy(results_, result_code, net_log_);
+    int rv = service_->DidFinishResolvingProxy(url_, load_flags_,
+                                               network_delegate_, results_,
+                                               result_code, net_log_);
 
     // Make a note in the results which configuration was in use at the
     // time of the resolve.
@@ -864,6 +872,8 @@ class ProxyService::PacRequest
   net::CompletionCallback user_callback_;
   ProxyInfo* results_;
   GURL url_;
+  int load_flags_;
+  NetworkDelegate* network_delegate_;
   ProxyResolver::RequestHandle resolve_job_;
   ProxyConfig::ID config_id_;  // The config id when the resolve was started.
   ProxyConfigSource config_source_;  // The source of proxy settings.
@@ -880,7 +890,7 @@ ProxyService::ProxyService(ProxyConfigService* config_service,
                            NetLog* net_log)
     : resolver_(resolver),
       next_config_id_(1),
-      current_state_(STATE_NONE) ,
+      current_state_(STATE_NONE),
       net_log_(net_log),
       stall_proxy_auto_config_delay_(TimeDelta::FromMilliseconds(
           kDelayAfterNetworkChangesMs)),
@@ -965,9 +975,11 @@ ProxyService* ProxyService::CreateFixedFromPacResult(
 }
 
 int ProxyService::ResolveProxy(const GURL& raw_url,
+                               int load_flags,
                                ProxyInfo* result,
                                const net::CompletionCallback& callback,
                                PacRequest** pac_request,
+                               NetworkDelegate* network_delegate,
                                const BoundNetLog& net_log) {
   DCHECK(CalledOnValidThread());
   DCHECK(!callback.is_null());
@@ -989,12 +1001,15 @@ int ProxyService::ResolveProxy(const GURL& raw_url,
 
   // Check if the request can be completed right away. (This is the case when
   // using a direct connection for example).
-  int rv = TryToCompleteSynchronously(url, result);
+  int rv = TryToCompleteSynchronously(url, load_flags,
+                                      network_delegate, result);
   if (rv != ERR_IO_PENDING)
-    return DidFinishResolvingProxy(result, rv, net_log);
+    return DidFinishResolvingProxy(url, load_flags, network_delegate,
+                                   result, rv, net_log);
 
   scoped_refptr<PacRequest> req(
-      new PacRequest(this, url, result, callback, net_log));
+      new PacRequest(this, url, load_flags, network_delegate,
+                     result, callback, net_log));
 
   if (current_state_ == STATE_READY) {
     // Start the resolve request.
@@ -1017,6 +1032,8 @@ int ProxyService::ResolveProxy(const GURL& raw_url,
 }
 
 int ProxyService::TryToCompleteSynchronously(const GURL& url,
+                                             int load_flags,
+                                             NetworkDelegate* network_delegate,
                                              ProxyInfo* result) {
   DCHECK_NE(STATE_NONE, current_state_);
 
@@ -1037,6 +1054,7 @@ int ProxyService::TryToCompleteSynchronously(const GURL& url,
   config_.proxy_rules().Apply(url, result);
   result->config_source_ = config_.source();
   result->config_id_ = config_.id();
+
   return OK;
 }
 
@@ -1166,10 +1184,12 @@ void ProxyService::OnInitProxyResolverComplete(int result) {
 }
 
 int ProxyService::ReconsiderProxyAfterError(const GURL& url,
+                                            int load_flags,
                                             int net_error,
                                             ProxyInfo* result,
                                             const CompletionCallback& callback,
                                             PacRequest** pac_request,
+                                            NetworkDelegate* network_delegate,
                                             const BoundNetLog& net_log) {
   DCHECK(CalledOnValidThread());
 
@@ -1183,7 +1203,8 @@ int ProxyService::ReconsiderProxyAfterError(const GURL& url,
     // If we have a new config or the config was never tried, we delete the
     // list of bad proxies and we try again.
     proxy_retry_info_.clear();
-    return ResolveProxy(url, result, callback, pac_request, net_log);
+    return ResolveProxy(url, load_flags, result, callback, pac_request,
+                        network_delegate, net_log);
   }
 
 #if defined(SPDY_PROXY_AUTH_ORIGIN)
@@ -1273,11 +1294,19 @@ void ProxyService::RemovePendingRequest(PacRequest* req) {
   pending_requests_.erase(it);
 }
 
-int ProxyService::DidFinishResolvingProxy(ProxyInfo* result,
+int ProxyService::DidFinishResolvingProxy(const GURL& url,
+                                          int load_flags,
+                                          NetworkDelegate* network_delegate,
+                                          ProxyInfo* result,
                                           int result_code,
                                           const BoundNetLog& net_log) {
   // Log the result of the proxy resolution.
   if (result_code == OK) {
+    // Allow the network delegate to interpose on the resolution decision,
+    // possibly modifying the ProxyInfo.
+    if (network_delegate)
+      network_delegate->NotifyResolveProxy(url, load_flags, result);
+
     // When logging all events is enabled, dump the proxy list.
     if (net_log.IsLogging()) {
       net_log.AddEvent(
@@ -1299,6 +1328,11 @@ int ProxyService::DidFinishResolvingProxy(ProxyInfo* result,
       // http://www.chromium.org/developers/design-documents/proxy-settings-fallback
       result->UseDirect();
       result_code = OK;
+
+      // Allow the network delegate to interpose on the resolution decision,
+      // possibly modifying the ProxyInfo.
+      if (network_delegate)
+        network_delegate->NotifyResolveProxy(url, load_flags, result);

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

Suggest getting rid of the redundant copy, and just putting:

if (result_code == OK && network_delegate)
  network_delegate->NotifyResolveProxy(url, load_flags, result);

at the end.

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

That was my original implementation, but I noticed that the net_log.AddEvent()
invocation on line 1312 references the result pointer. If I put my conditional
at the end, it would log the wrong resolver if the callback decides to bypass
the DCP.

     } else {
       result_code = ERR_MANDATORY_PROXY_CONFIGURATION_FAILED;
     }
@@ -1623,7 +1657,7 @@ SyncProxyServiceHelper::~SyncProxyServiceHelper() {}
 void SyncProxyServiceHelper::StartAsyncResolve(const GURL& url,
                                                const BoundNetLog& net_log) {
   result_ = proxy_service_->ResolveProxy(
-      url, &proxy_info_, callback_, NULL, net_log);
+      url, net::LOAD_NORMAL, &proxy_info_, callback_, NULL, NULL, net_log);
   if (result_ != net::ERR_IO_PENDING) {
     OnCompletion(result_);
   }
@@ -1633,7 +1667,8 @@ void SyncProxyServiceHelper::StartAsyncReconsider(const GURL& url,
                                                   int net_error,
                                                   const BoundNetLog& net_log) {
   result_ = proxy_service_->ReconsiderProxyAfterError(
-      url, net_error, &proxy_info_, callback_, NULL, net_log);
+      url, net::LOAD_NORMAL, net_error, &proxy_info_, callback_, NULL, NULL,
+      net_log);
   if (result_ != net::ERR_IO_PENDING) {
     OnCompletion(result_);
   }