Change ProxyRules to handle ProxyLists rather than just single ProxyServer instances.

net/proxy/proxy_config.h

Index: net/proxy/proxy_config.h
diff --git a/net/proxy/proxy_config.h b/net/proxy/proxy_config.h
index 29619dff1e36ae3cd4ac02e96365b660b2817ef4..75943b5ef64b7c40e167c172586e0d6a28968450 100644
--- a/net/proxy/proxy_config.h
+++ b/net/proxy/proxy_config.h
@@ -11,6 +11,7 @@
 #include "net/base/net_export.h"
 #include "net/proxy/proxy_bypass_rules.h"
 #include "net/proxy/proxy_config_source.h"
+#include "net/proxy/proxy_list.h"
 #include "net/proxy/proxy_server.h"
 
 namespace base {
@@ -52,17 +53,23 @@ class NET_EXPORT ProxyConfig {
       return type == TYPE_NO_RULES;
     }
 
-    // Sets |result| with the proxy to use for |url| based on the current rules.
+    // Sets |result| with the proxies to use for |url| based on the current
+    // rules.
     void Apply(const GURL& url, ProxyInfo* result) const;
 
     // Parses the rules from a string, indicating which proxies to use.
     //
     //   proxy-uri = [<proxy-scheme>"://"]<proxy-host>[":"<proxy-port>]
     //
+    //   proxy-uri-list = <proxy-uri>[","<proxy-uri-list>]
+    //
     // If the proxy to use depends on the scheme of the URL, can instead specify
     // a semicolon separated list of:
     //
-    //   <url-scheme>"="<proxy-uri>
+    //   <url-scheme>"="<proxy-uri-list>
+    //
+    // If 'socks' is specified as a scheme, any schemes left without proxies
+    // specified will have that 'socks' server added.
     //
     // For example:
     //   "http=foopy:80;ftp=foopy2"  -- use HTTP proxy "foopy:80" for http://
@@ -71,12 +78,21 @@ class NET_EXPORT ProxyConfig {
     //   "foopy:80"                  -- use HTTP proxy "foopy:80" for all URLs.

[eroman, 2013/03/01 00:05:13]

It would make sense for proxy-uri-list to also be supported without any schemes.
For instance the input:

"foopy:80,fallback1,direct://"

[marq_use_my_chromium_address, 2013/03/04 18:04:20]

Done.

     //   "socks4://foopy"            -- use SOCKS v4 proxy "foopy:1080" for all
     //                                  URLs.
+    //   "http=foopy,bar.com         -- use HTTP proxy "foopy" for http URLs,
+    //                                  and fail over to "bar.com" if "foopy"
+    //                                  is unavailable.
+    //   "http=foopy,direct://       -- use HTTP proxy "foopy" for http URLs,
+    //                                  and use no proxy if "foopy" is
+    //                                  unavailable.
+    //   "http=foopy;socks=foopy2   --  use HTTP proxy "foopy" for http URLs,
+    //                                  and use socks4://foopy2 for all other
+    //                                  URLs.
     void ParseFromString(const std::string& proxy_rules);
 
     // Returns one of {&proxy_for_http, &proxy_for_https, &proxy_for_ftp,

[eroman, 2013/03/01 00:05:13]

Please update this comment to reflect new names.

[marq_use_my_chromium_address, 2013/03/04 18:04:20]

Done.

     // &fallback_proxy}, or NULL if there is no proxy to use.
     // Should only call this if the type is TYPE_PROXY_PER_SCHEME.
-    const ProxyServer* MapUrlSchemeToProxy(const std::string& url_scheme) const;
+    const ProxyList* MapUrlSchemeToProxy(const std::string& url_scheme) const;

[eroman, 2013/03/01 00:05:13]

Can you rename "ToProxy" --> "ToProxies" or "ToProxyList"

[marq_use_my_chromium_address, 2013/03/04 18:04:20]

Done.

 
     // Returns true if |*this| describes the same configuration as |other|.
     bool Equals(const ProxyRules& other) const;
@@ -90,21 +106,22 @@ class NET_EXPORT ProxyConfig {
     Type type;
 
     // Set if |type| is TYPE_SINGLE_PROXY.
-    ProxyServer single_proxy;
+    ProxyList single_proxies;

[eroman, 2013/03/01 00:05:13]

Side-comment [no action necessary]: Can probably just get rid of this, and use
|fallback_proxies| instead.

[marq_use_my_chromium_address, 2013/03/04 18:04:20]

Ack.

 
     // Set if |type| is TYPE_PROXY_PER_SCHEME.
-    ProxyServer proxy_for_http;
-    ProxyServer proxy_for_https;
-    ProxyServer proxy_for_ftp;
+    ProxyList proxies_for_http;
+    ProxyList proxies_for_https;
+    ProxyList proxies_for_ftp;
 
-    // Used when there isn't a more specific per-scheme proxy server.
-    ProxyServer fallback_proxy;
+    // Used when a fallback has been defined and the url to be proxied doesn't
+    // match any of the standard schemes.
+    ProxyList fallback_proxies;
 
    private:
     // Returns one of {&proxy_for_http, &proxy_for_https, &proxy_for_ftp}

[eroman, 2013/03/01 00:05:13]

Please update this comment.

[marq_use_my_chromium_address, 2013/03/04 18:04:20]

Done.

     // or NULL if it is a scheme that we don't have a mapping
     // for. Should only call this if the type is TYPE_PROXY_PER_SCHEME.
-    ProxyServer* MapUrlSchemeToProxyNoFallback(const std::string& scheme);
+    ProxyList* MapUrlSchemeToProxyNoFallback(const std::string& scheme);

[eroman, 2013/03/01 00:05:13]

See earlier rename suggestion.

[marq_use_my_chromium_address, 2013/03/04 18:04:20]

Done.

   };
 
   typedef int ID;