Enable cookies per default in net. Add an API to disable them by default, and do that in Chrome

net/url_request/url_request.h

Index: net/url_request/url_request.h
diff --git a/net/url_request/url_request.h b/net/url_request/url_request.h
index d73d2fec6a34b05861710e347ab248404af8bb18..e204c6b3fd4e3eb9a179ca40ee9e8fbe5e16a7c4 100644
--- a/net/url_request/url_request.h
+++ b/net/url_request/url_request.h
@@ -291,6 +291,14 @@ class NET_EXPORT URLRequest : NON_EXPORTED_BASE(public base::NonThreadSafe),
   // will not have any more of its methods called.
   virtual ~URLRequest();
 
+  // Changes the default cookie policy from allowing all cookies to blocking all
+  // cookies. Embedders that want to implement a more flexible policy should
+  // change the default to blocking all cookies, and provide a NetworkDelegate
+  // with the URLRequestContext that maintains the CookieStore.
+  // The cookie policy default has to be set before the first URLRequest is
+  // started. Once it was set to block all cookies, it cannot be changed back.
+  static void SetDefaultCookiePolicyToBlock();
+
   // Returns true if the scheme can be handled by URLRequest. False otherwise.
   static bool IsHandledProtocol(const std::string& scheme);