Add some plumbing for in-progress work on enabling SSL proxy support....

net/proxy/proxy_info.h

Index: net/proxy/proxy_info.h
===================================================================
--- net/proxy/proxy_info.h	(revision 52951)
+++ net/proxy/proxy_info.h	(working copy)
@@ -50,7 +50,14 @@
     return proxy_list_.Get().is_direct();
   }
 
-  // Returns true if the first valid proxy server is a http proxy.
+  // Returns true if the first valid proxy server is an https proxy.
+  bool is_https() const {
+    if (is_empty())
+      return false;
+    return proxy_server().is_https();
+  }
+
+  // Returns true if the first valid proxy server is an http proxy.
   bool is_http() const {
     if (is_empty())
       return false;