Give prerendering RVH's RenderWidgetHostViews.

chrome/browser/prerender/prerender_manager.cc

Index: chrome/browser/prerender/prerender_manager.cc
===================================================================
--- chrome/browser/prerender/prerender_manager.cc	(revision 82104)
+++ chrome/browser/prerender/prerender_manager.cc	(working copy)
@@ -134,9 +134,11 @@
   prerender_contents_factory_.reset(prerender_contents_factory);
 }
 
-bool PrerenderManager::AddPreload(const GURL& url,
-                                  const std::vector<GURL>& alias_urls,
-                                  const GURL& referrer) {
+bool PrerenderManager::AddPreload(
+    const std::pair<int, int>& child_route_id_pair,
+    const GURL& url,
+    const std::vector<GURL>& alias_urls,
+    const GURL& referrer) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DeleteOldEntries();
   if (FindEntry(url))
@@ -177,6 +179,18 @@
     return false;
   }
 
+  RenderViewHost* source_render_view_host = NULL;
+  // This test should fail only during unit tests.
+  if (child_route_id_pair.first != -1) {
+    source_render_view_host =
+        RenderViewHost::FromID(child_route_id_pair.first,
+                               child_route_id_pair.second);
+    // Don't prerender page if parent RenderViewHost no longer exists, or it has
+    // no view.  The latter should only happen when the RenderView has closed.

[cbentzel, 2011/04/19 17:42:41]

Is it possible to add a browser test [or at least a unit test] where this case
happens? It sounds like it will be tricky to do due to tight timing, but might
be a good idea. Skipping the prerender in this case makes sense, regardless of
getting the view extents. 

[mmenke, 2011/04/19 20:00:01]

I'm not sure about a browser test using our current framework.  Simplest way may
be to create a TestPrerenderManager and have it destroy the original
RenderViewHost in AddPreload.

I suppose we could create a prerender request for a non-existent RenderView in a
browser test, but at that point, I'm not sure how much we gain from not just
doing a unit test instead.

I've added the aforementioned unit test, and I've filed a bug for a browser
test.

Also, I added a FinalStatus for cancelling in this case, which I had forgotten
to do.

+    if (!source_render_view_host || !source_render_view_host->view())
+      return false;
+  }
+
   // TODO(cbentzel): Move invalid checks here instead of PrerenderContents?
   PrerenderContentsData data(CreatePrerenderContents(url, all_alias_urls,
                                                      referrer),
@@ -187,7 +201,7 @@
     data.contents_->set_final_status(FINAL_STATUS_CONTROL_GROUP);
   } else {
     last_prerender_start_time_ = GetCurrentTimeTicks();
-    data.contents_->StartPrerendering();
+    data.contents_->StartPrerendering(source_render_view_host);
   }
   while (prerender_list_.size() > max_elements_) {
     data = prerender_list_.front();
@@ -200,7 +214,7 @@
 }
 
 void PrerenderManager::AddPendingPreload(
-    const std::pair<int,int>& child_route_id_pair,
+    const std::pair<int, int>& child_route_id_pair,
     const GURL& url,
     const std::vector<GURL>& alias_urls,
     const GURL& referrer) {
@@ -246,14 +260,20 @@
 }
 
 void PrerenderManager::DeleteOldEntries() {
-  while (!prerender_list_.empty()) {
-    PrerenderContentsData data = prerender_list_.front();
-    if (IsPrerenderElementFresh(data.start_time_))
-      return;
-    prerender_list_.pop_front();
-    data.contents_->set_final_status(FINAL_STATUS_TIMED_OUT);
-    delete data.contents_;
+  std::list<PrerenderContentsData>::iterator it = prerender_list_.begin();
+  while (it != prerender_list_.end()) {
+    if (it->contents_->pending_final_status() != FINAL_STATUS_MAX) {
+      it->contents_->set_final_status(it->contents_->pending_final_status());
+    } else if (!IsPrerenderElementFresh(it->start_time_)) {
+      it->contents_->set_final_status(FINAL_STATUS_TIMED_OUT);
+    } else {
+      ++it;
+      continue;
+    }
+    delete it->contents_;
+    it = prerender_list_.erase(it);
   }
+
   if (prerender_list_.empty())
     StopSchedulingPeriodicCleanups();
 }
@@ -317,7 +337,7 @@
     for (std::vector<PendingContentsData>::iterator content_it =
             pending_it->second.begin();
          content_it != pending_it->second.end(); ++content_it) {
-      AddPreload(content_it->url_, content_it->alias_urls_,
+      AddPreload(pending_it->first, content_it->url_, content_it->alias_urls_,
                  content_it->referrer_);
     }
     pending_prerender_list_.erase(pending_it);