Allow prerendering in single-process mode.

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 "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/time.h"
@@ skipping 137 matching lines @@
   GURL additional_alias_url;
   if (IsControlGroup() &&
       PrerenderManager::MaybeGetQueryStringBasedAliasURL(
           url, &additional_alias_url))
     all_alias_urls.push_back(additional_alias_url);
 
   // Do not prerender if there are too many render processes, and we would
   // have to use an existing one.  We do not want prerendering to happen in
   // a shared process, so that we can always reliably lower the CPU
   // priority for prerendering.
+  // In single-process mode, ShouldTryToUseExistingProcessHost() always returns
+  // true, so that case needs to be explicitly checked for.
   // TODO(tburkard): Figure out how to cancel prerendering in the opposite
   // case, when a new tab is added to a process used for prerendering.
-  if (RenderProcessHost::ShouldTryToUseExistingProcessHost()) {
+  if (RenderProcessHost::ShouldTryToUseExistingProcessHost() &&
+      !RenderProcessHost::run_renderer_in_process()) {
     // Only record the status if we are not in the control group.
     if (!IsControlGroup())
       RecordFinalStatus(FINAL_STATUS_TOO_MANY_PROCESSES);
     return false;
   }
 
   // Check if enough time has passed since the last prerender.
   if (!DoesRateLimitAllowPrerender()) {
     // Cancel the prerender. We could add it to the pending prerender list but
     // this doesn't make sense as the next prerender request will be triggered
@@ skipping 405 matching lines @@
 
 bool PrerenderManager::IsTabContentsPrerendered(TabContents* tc) const {
   return prerendered_tc_set_.count(tc) > 0;
 }
 
 bool PrerenderManager::WouldTabContentsBePrerendered(TabContents* tc) const {
   return would_be_prerendered_tc_set_.count(tc) > 0;
 }
 
 }  // namespace prerender