Do speculative preconnection based on network traffic (not just DNS)

This rev also handles the triple of scheme/host/port for recording
both referrers and speculative connections, so that we
can soon support SSL warming as well as "mere" TCP/IP
preconnection.

r=mbelshe
Review URL: http://codereview.chromium.org/2563004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50563 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 41 insertions, 0 deletions

diff --git a/chrome/browser/net/connect_interceptor.cc b/chrome/browser/net/connect_interceptor.cc
new file mode 100644
index 0000000..ab45ddb
--- /dev/null
+++ b/chrome/browser/net/connect_interceptor.cc
@@ -0,0 +1,41 @@
+// 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/connect_interceptor.h"
+
+#include "chrome/browser/net/dns_global.h"
+
+namespace chrome_browser_net {
+
+ConnectInterceptor::ConnectInterceptor() {
+  URLRequest::RegisterRequestInterceptor(this);
+}
+
+ConnectInterceptor::~ConnectInterceptor() {
+  URLRequest::UnregisterRequestInterceptor(this);
+}
+
+URLRequestJob* ConnectInterceptor::MaybeIntercept(URLRequest* request) {
+  if (!request->referrer().empty()) {
+    // Learn about our referring URL, for use in the future.
+    GURL referring_url(GURL(request->referrer()).GetWithEmptyPath());
+    // TODO(jar): Only call if we think this was part of a frame load, and not a
+    // link navigation.  For now, we'll "learn" that to preconnect when a user
+    // actually does a click... which will probably waste space in our referrers
+    // table (since it probably won't be that deterministic).
+    NonlinkNavigation(referring_url, request->url().GetWithEmptyPath());
+  }
+  // Now we use previous learning and setup for our subresources.
+  if (request->was_fetched_via_proxy())
+    return NULL;
+  // TODO(jar): Only call if we believe this is a frame, and might have
+  // subresources.  We could "guess" by looking at path extensions (such as
+  // foo.jpg or goo.gif etc.), but better would be to get this info from webkit
+  // and have it add the info to the request (we currently only set the
+  // priority, but we could record whether it was a frame).
+  NavigatingToFrame(request->url().GetWithEmptyPath());
+  return NULL;
+}
+
+}  // namespace chrome_browser_net