Abandon prerenders upon render thread shutdown.

chrome/renderer/prerender/prerender_dispatcher.cc

 // Copyright (c) 2012 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/renderer/prerender/prerender_dispatcher.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "chrome/common/prerender_messages.h"
@@ skipping 156 matching lines @@
       PrerenderExtraData::FromPrerender(prerender);
   content::RenderThread::Get()->Send(
       new PrerenderHostMsg_AbandonLinkRelPrerender(extra_data.prerender_id()));
   // The browser will not send an OnPrerenderStop (the prerender may have even
   // been canceled before it was started), so release it to avoid a
   // leak. Moreover, if it did, the PrerenderClient in Blink will have been
   // detached already.
   prerenders_.erase(extra_data.prerender_id());
 }
 
+void PrerenderDispatcher::detachRenderer() {
+  // Blink is shutting down, abandon all in-flight prerenders.
+  for (auto it : prerenders_) {
+    const PrerenderExtraData& extra_data =
+        PrerenderExtraData::FromPrerender(it.second);
+    content::RenderThread::Get()->Send(
+        new PrerenderHostMsg_AbandonLinkRelPrerender(
+            extra_data.prerender_id()));
+  }
+  prerenders_.clear();
+}
+
 }  // namespace prerender