Support both preconnection, and pre-resolution for subresources...

chrome/browser/net/connect_interceptor.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/connect_interceptor.h"
 
 #include "chrome/browser/net/predictor_api.h"
+#include "net/base/load_flags.h"
 
 namespace chrome_browser_net {
 
 ConnectInterceptor::ConnectInterceptor() {
   URLRequest::RegisterRequestInterceptor(this);
 }
 
 ConnectInterceptor::~ConnectInterceptor() {
   URLRequest::UnregisterRequestInterceptor(this);
 }
 
 URLRequestJob* ConnectInterceptor::MaybeIntercept(URLRequest* request) {
-  if (!request->referrer().empty()) {
+  bool is_subresource = !(request->load_flags() & net::LOAD_MAIN_FRAME);
+  if (is_subresource && !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).
-    LearnFromNavigation(referring_url, request->url().GetWithEmptyPath());
+    GURL referring_url(request->referrer());
+    LearnFromNavigation(referring_url.GetWithEmptyPath(),
+                        request->url().GetWithEmptyPath());
   }
+  bool is_frame = 0 != (request->load_flags() & (net::LOAD_SUB_FRAME |
+                                                 net::LOAD_MAIN_FRAME));
   // 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).
-  PredictFrameSubresources(request->url().GetWithEmptyPath());
+  if (is_frame && !request->was_fetched_via_proxy())
+    PredictFrameSubresources(request->url().GetWithEmptyPath());
   return NULL;
 }
 
 }  // namespace chrome_browser_net