Handle AddPreload/AddPendingPreload on UI thread.

chrome/browser/prerender/prerender_manager.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/prerender/prerender_manager.h"
 
 #include <string>
 
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
@@ skipping 155 matching lines @@
   ~PendingContentsData() {}
   GURL url_;
   GURL referrer_;
 };
 
 void HandleTag(
     const base::WeakPtr<PrerenderManager>& prerender_manager_weak_ptr,
     int render_process_id,
     int render_view_id,
     const GURL& url,
-    const GURL& referrer,
-    bool make_pending) {
+    const GURL& referrer) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   PrerenderManager* prerender_manager = prerender_manager_weak_ptr.get();
   if (!prerender_manager || !prerender_manager->is_enabled())
     return;
   prerender_manager->RecordTagObserved();
 
   std::pair<int, int> child_route_id_pair = std::make_pair(render_process_id,
                                                            render_view_id);
-  // TODO(cbentzel): Should the decision to make pending be done on the
-  //                 UI thread rather than the IO thread? The page may have
-  //                 become activated at this point.
-  if (make_pending)
-    prerender_manager->AddPendingPreload(child_route_id_pair, url, referrer);
-  else
-    prerender_manager->AddPreload(child_route_id_pair, url, referrer);
+
+  prerender_manager->AddPreload(child_route_id_pair, url, referrer);
 }
 
 void DestroyPreloadForRenderView(
     const base::WeakPtr<PrerenderManager>& prerender_manager_weak_ptr,
     int render_process_id,
     int render_view_id,
     FinalStatus final_status) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   PrerenderManager* prerender_manager = prerender_manager_weak_ptr.get();
   if (!prerender_manager)
@@ skipping 38 matching lines @@
     PrerenderContents::Factory* prerender_contents_factory) {
   DCHECK(CalledOnValidThread());
   prerender_contents_factory_.reset(prerender_contents_factory);
 }
 
 bool PrerenderManager::AddPreload(
     const std::pair<int, int>& child_route_id_pair,
     const GURL& url_arg,
     const GURL& referrer) {
   DCHECK(CalledOnValidThread());
+
+  // If the referring page is prerendering, defer the prerender.
+  if (FindPrerenderContentsForChildRouteIdPair(child_route_id_pair) !=
+          prerender_list_.end()) {
+    AddPendingPreload(child_route_id_pair, url_arg, referrer);
+    return true;
+  }
+
   DeleteOldEntries();
   DeletePendingDeleteEntries();
 
   GURL url = url_arg;
   GURL alias_url;
   if (IsControlGroup() &&
       PrerenderManager::MaybeGetQueryStringBasedAliasURL(
           url, &alias_url)) {
     url = alias_url;
   }
@@ skipping 59 matching lines @@
     data.contents_->Destroy(FINAL_STATUS_EVICTED);
   }
   StartSchedulingPeriodicCleanups();
   return true;
 }
 
 void PrerenderManager::AddPendingPreload(
     const std::pair<int, int>& child_route_id_pair,
     const GURL& url,
     const GURL& referrer) {
-  DCHECK(CalledOnValidThread());
-  // Check if this is coming from a valid prerender RenderViewHost.
-  bool is_valid_prerender =
-      (FindPrerenderContentsForChildRouteIdPair(child_route_id_pair) !=
-       prerender_list_.end());
-
-  // If not, we could check to see if the RenderViewHost specified by the
-  // child_route_id_pair exists and if so just start prerendering, as this
-  // suggests that the link was clicked, though this might prerender something
-  // that the user has already navigated away from. For now, we'll be
-  // conservative and skip the prerender which will mean some prerender requests
-  // from prerendered pages will be missed if the user navigates quickly.
-  if (!is_valid_prerender) {
-    RecordFinalStatus(FINAL_STATUS_PENDING_SKIPPED);
-    return;
-  }
-
+  DCHECK(FindPrerenderContentsForChildRouteIdPair(child_route_id_pair) !=
+             prerender_list_.end());
   PendingPrerenderList::iterator it =
       pending_prerender_list_.find(child_route_id_pair);
   if (it == pending_prerender_list_.end()) {
     PendingPrerenderList::value_type el = std::make_pair(child_route_id_pair,
                                             std::vector<PendingContentsData>());
     it = pending_prerender_list_.insert(el).first;
   }
 
   it->second.push_back(PendingContentsData(url, referrer));
 }
@@ skipping 655 matching lines @@
   base::TimeTicks cutoff = GetCurrentTimeTicks() -
       base::TimeDelta::FromMilliseconds(kNavigationRecordWindowMs);
   while (!navigations_.empty()) {
     if (navigations_.front().time_ > cutoff)
       break;
     navigations_.pop_front();
   }
 }
 
 }  // namespace prerender