Adds support for the DHCP portion of the WPAD (proxy auto-discovery) protocol.

net/proxy/proxy_script_fetcher.h

Index: net/proxy/proxy_script_fetcher.h
diff --git a/net/proxy/proxy_script_fetcher.h b/net/proxy/proxy_script_fetcher.h
index c8cda247e72f107cda042e8be6d1387806b09a57..ae925082c267d1df5dbcb76f61d5958926d0892d 100644
--- a/net/proxy/proxy_script_fetcher.h
+++ b/net/proxy/proxy_script_fetcher.h
@@ -26,7 +26,7 @@ class ProxyScriptFetcher {
   // Destruction should cancel any outstanding requests.
   virtual ~ProxyScriptFetcher() {}
 
-  // Downloads the given PAC URL, and invokes |callback| on completion.
+  // Downloads a PAC script, and invokes |callback| on completion.
   // Returns OK on success, otherwise the error code. If the return code is
   // ERR_IO_PENDING, then the request completes asynchronously, and |callback|
   // will be invoked later with the final error code.
@@ -44,7 +44,7 @@ class ProxyScriptFetcher {
   // deleting |this|), then no callback is invoked.
   //
   // Only one fetch is allowed to be outstanding at a time.
-  virtual int Fetch(const GURL& url, string16* utf16_text,
+  virtual int Fetch(string16* utf16_text,
                     CompletionCallback* callback) = 0;
 
   // Aborts the in-progress fetch (if any).
@@ -52,7 +52,14 @@ class ProxyScriptFetcher {
 
   // Returns the request context that this fetcher uses to issue downloads,
   // or NULL.
-  virtual URLRequestContext* GetRequestContext() = 0;
+  virtual URLRequestContext* GetRequestContext() const = 0;
+};
+
+// A proxy script fetcher that fetches a specific URL.
+class URLProxyScriptFetcher : public ProxyScriptFetcher {
+public:
+  // Sets the URL to retrieve when Fetch() is called.
+  virtual void SetURL(const GURL& url) = 0;
 };
 
 }  // namespace net