Reland 54771 (and 54795) To enable TCP Preconnection by default...

chrome/browser/net/predictor.cc

 // Copyright (c) 2010 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/net/predictor.h"
 
 #include <algorithm>
 #include <set>
 #include <sstream>
 
@@ skipping 131 matching lines @@
   TOO_NEW,
   SUBRESOURCE_VALUE_MAX
 };
 
 void Predictor::PredictFrameSubresources(const GURL& url) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
   DCHECK(url.GetWithEmptyPath() == url);
   Referrers::iterator it = referrers_.find(url);
   if (referrers_.end() == it)
     return;
+  ChromeThread::PostTask(
+      ChromeThread::IO,
+      FROM_HERE,
+      NewRunnableMethod(this,
+                        &Predictor::PrepareFrameSubresources, url));
+}
+
+void Predictor::PrepareFrameSubresources(const GURL& url) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+  DCHECK(url.GetWithEmptyPath() == url);
+  Referrers::iterator it = referrers_.find(url);
+  if (referrers_.end() == it)
+    return;
+
   Referrer* referrer = &(it->second);
   referrer->IncrementUseCount();
   const UrlInfo::ResolutionMotivation motivation =
       UrlInfo::LEARNED_REFERAL_MOTIVATED;
   for (Referrer::iterator future_url = referrer->begin();
        future_url != referrer->end(); ++future_url) {
     SubresourceValue evalution(TOO_NEW);
     double connection_expectation = future_url->second.subresource_use_rate();
     UMA_HISTOGRAM_CUSTOM_COUNTS("Net.PreconnectSubresourceExpectation",
                                 static_cast<int>(connection_expectation * 100),
@@ skipping 398 matching lines @@
 GURL Predictor::HostNameQueue::Pop() {
   DCHECK(!IsEmpty());
   std::queue<GURL> *queue(rush_queue_.empty() ? &background_queue_
                                               : &rush_queue_);
   GURL url(queue->front());
   queue->pop();
   return url;
 }
 
 }  // namespace chrome_browser_net