Abandon prerenders upon render thread shutdown.

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 5e616b01a17ed217a28cd12bef0998c057a7189e..1ef433009becb2513872df90e3723d1fde101dca 100644
--- a/chrome/renderer/prerender/prerender_dispatcher.cc
+++ b/chrome/renderer/prerender/prerender_dispatcher.cc
@@ -127,6 +127,18 @@ bool PrerenderDispatcher::OnControlMessageReceived(
   return handled;
 }
 
+void PrerenderDispatcher::OnRenderProcessShutdown() {
+  // Renderer 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();
+}
+
 void PrerenderDispatcher::add(const WebPrerender& prerender) {
   const PrerenderExtraData& extra_data =
       PrerenderExtraData::FromPrerender(prerender);