Only commit cookie changes in prerenders after a prerender is shown

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
===================================================================
--- chrome/browser/chrome_content_browser_client.cc	(revision 269781)
+++ chrome/browser/chrome_content_browser_client.cc	(working copy)
@@ -630,7 +630,8 @@
 
 namespace chrome {
 
-ChromeContentBrowserClient::ChromeContentBrowserClient() {
+ChromeContentBrowserClient::ChromeContentBrowserClient()
+    : prerender_tracker_(NULL) {
 #if defined(ENABLE_PLUGINS)
   for (size_t i = 0; i < arraysize(kPredefinedAllowedFileHandleOrigins); ++i)
     allowed_file_handle_origins_.insert(kPredefinedAllowedFileHandleOrigins[i]);
@@ -1214,6 +1215,24 @@
       privilege_required;
 }
 
+bool ChromeContentBrowserClient::MayReuseHost(
+    content::RenderProcessHost* process_host) {
+  // If there is currently a prerender in progress for the host provided,
+  // it may not be shared. We require prerenders to be by themselves in a
+  // separate process, so that we can monitor their resource usage, and so that
+  // we can track the cookies that they change.
+  Profile* profile = Profile::FromBrowserContext(
+      process_host->GetBrowserContext());
+  prerender::PrerenderManager* prerender_manager =
+      prerender::PrerenderManagerFactory::GetForProfile(profile);
+  if (prerender_manager &&
+      prerender_manager->IsProcessPrerendering(process_host)) {
+    return false;
+  }
+
+  return true;
+}
+
 // This function is trying to limit the amount of processes used by extensions
 // with background pages. It uses a globally set percentage of processes to
 // run such extensions and if the limit is exceeded, it returns true, to
@@ -1765,6 +1784,13 @@
   CookieSettings* cookie_settings = io_data->GetCookieSettings();
   bool allow = cookie_settings->IsSettingCookieAllowed(url, first_party);
 
+  if (prerender_tracker_) {
+    prerender_tracker_->OnCookieChangedForURL(
+        render_process_id,
+        context->GetRequestContext()->cookie_store()->GetCookieMonster(),
+        url);
+  }
+
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&TabSpecificContentSettings::CookieChanged, render_process_id,
@@ -2211,6 +2237,8 @@
 }
 
 void ChromeContentBrowserClient::ResourceDispatcherHostCreated() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  prerender_tracker_ = g_browser_process->prerender_tracker();
   return g_browser_process->ResourceDispatcherHostCreated();
 }
 
@@ -2698,6 +2726,16 @@
 #endif
 }
 
+net::CookieStore*
+ChromeContentBrowserClient::OverrideCookieStoreForRenderProcess(
+    int render_process_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (!prerender_tracker_)
+    return NULL;
+  return prerender_tracker_->
+      GetPrerenderCookieStoreForRenderProcess(render_process_id);
+}
+
 #if defined(ENABLE_WEBRTC)
 void ChromeContentBrowserClient::MaybeCopyDisableWebRtcEncryptionSwitch(
     CommandLine* to_command_line,