Add Start/Stop event signalling on Prerenders.

chrome/renderer/prerender/prerender_dispatcher.cc

Index: chrome/renderer/prerender/prerender_dispatcher.cc
diff --git a/chrome/renderer/prerender/prerender_dispatcher.cc b/chrome/renderer/prerender/prerender_dispatcher.cc
index 3c1a9046df910cac497d615507185bf0456221a3..88cf06a1ffcb21ba9ff978788e0164c645d8e9cb 100644
--- a/chrome/renderer/prerender/prerender_dispatcher.cc
+++ b/chrome/renderer/prerender/prerender_dispatcher.cc
@@ -35,12 +35,19 @@ bool PrerenderDispatcher::IsPrerenderURL(const GURL& url) const {
 }
 
 void PrerenderDispatcher::OnPrerenderStart(int prerender_id) {
-  std::map<int, GURL>::iterator it = prerenders_.find(prerender_id);
+  std::map<int, WebPrerender>::iterator it = prerenders_.find(prerender_id);
   if (it == prerenders_.end())
     return;
-  const GURL& url = it->second;
+
+  WebPrerender& prerender = it->second;
+
+  // The prerender should only be null in unit tests.
+  if (prerender.isNull())
+    return;
+
+  prerender.didStartPrerender();
   running_prerender_urls_.insert(
-      std::multimap<GURL, int>::value_type(url, prerender_id));
+      std::multimap<GURL, int>::value_type(prerender.url(), prerender_id));
 }
 
 void PrerenderDispatcher::OnPrerenderAddAlias(int prerender_id,
@@ -53,14 +60,20 @@ void PrerenderDispatcher::OnPrerenderAddAlias(int prerender_id,
 void PrerenderDispatcher::OnPrerenderStop(int prerender_id) {
   // It's possible we will receive a spurious remove, so we don't crash in that
   // situation.
-  if (prerenders_.count(prerender_id) == 0)
+  std::map<int, WebPrerender>::iterator it = prerenders_.find(prerender_id);
+  if (it == prerenders_.end())
     return;
+  WebPrerender& prerender = it->second;
+
+  // The prerender should only be null in unit tests.
+  if (!prerender.isNull())
+    prerender.didStopPrerender();
 
   // TODO(cbentzel): We'd also want to send the map of active prerenders when
   // creating a new render process, so the Add/Remove go relative to that.
   // This may not be that big of a deal in practice, since the newly created tab
   // is unlikely to go to the prerendered page.
-  prerenders_.erase(prerender_id);
+  prerenders_.erase(it);
 
   std::stack<std::multimap<GURL, int>::iterator> to_delete;
   for (std::multimap<GURL, int>::iterator it = running_prerender_urls_.begin();
@@ -87,26 +100,28 @@ bool PrerenderDispatcher::OnControlMessageReceived(
   return handled;
 }
 
-void PrerenderDispatcher::add(const WebKit::WebPrerender& prerender) {
+void PrerenderDispatcher::add(const WebPrerender& prerender) {
   const PrerenderExtraData& extra_data =
       PrerenderExtraData::FromPrerender(prerender);
-  prerenders_.insert(std::map<int, GURL>::value_type(extra_data.prerender_id(),
-                                                     prerender.url()));
+  prerenders_.insert(
+      std::map<int, WebPrerender>::value_type(extra_data.prerender_id(),
+                                              prerender));

[mmenke, 2012/12/07 17:11:48]

It looks like we currently eternally accumulate prerenders here if they aren't
started in the browser, even if webkit cancels/abandons them.  Am I missing
something?

[gavinp, 2012/12/14 21:48:52]

No, nothing. But the new uploads should clean that up some.

 
   content::RenderThread::Get()->Send(new PrerenderHostMsg_AddLinkRelPrerender(
       extra_data.prerender_id(), GURL(prerender.url()),
-      content::Referrer(GURL(prerender.referrer()), prerender.referrerPolicy()),
+      content::Referrer(GURL(prerender.referrer()),
+                        prerender.referrerPolicy()),
       extra_data.size(), extra_data.render_view_route_id()));
 }
 
-void PrerenderDispatcher::cancel(const WebKit::WebPrerender& prerender) {
+void PrerenderDispatcher::cancel(const WebPrerender& prerender) {
   const PrerenderExtraData& extra_data =
       PrerenderExtraData::FromPrerender(prerender);
   content::RenderThread::Get()->Send(
       new PrerenderHostMsg_CancelLinkRelPrerender(extra_data.prerender_id()));
 }
 
-void PrerenderDispatcher::abandon(const WebKit::WebPrerender& prerender) {
+void PrerenderDispatcher::abandon(const WebPrerender& prerender) {
   const PrerenderExtraData& extra_data =
       PrerenderExtraData::FromPrerender(prerender);
   content::RenderThread::Get()->Send(