Only commit cookie changes in prerenders after a prerender is shown

chrome/browser/net/chrome_network_delegate.h

Index: chrome/browser/net/chrome_network_delegate.h
===================================================================
--- chrome/browser/net/chrome_network_delegate.h	(revision 270027)
+++ chrome/browser/net/chrome_network_delegate.h	(working copy)
@@ -49,6 +49,10 @@
 class URLBlacklistManager;
 }
 
+namespace prerender {
+class PrerenderTracker;
+}
+
 // ChromeNetworkDelegate is the central point from within the chrome code to
 // add hooks into the network stack.
 class ChromeNetworkDelegate : public net::NetworkDelegate {
@@ -106,6 +110,10 @@
     domain_reliability_monitor_ = domain_reliability_monitor;
   }
 
+  void set_prerender_tracker(prerender::PrerenderTracker* prerender_tracker) {
+    prerender_tracker_ = prerender_tracker;
+  }
+
   // Adds the Client Hints header to HTTP requests.
   void SetEnableClientHints();
 
@@ -228,6 +236,8 @@
 
   bool first_request_;
 
+  prerender::PrerenderTracker* prerender_tracker_;
+
   DISALLOW_COPY_AND_ASSIGN(ChromeNetworkDelegate);
 };