Add metrics for calculating precision/recall of link navigation pre-connect triggers.

chrome/browser/net/predictor_tab_helper.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/browser/net/predictor_tab_helper.h"
+
+#include "chrome/browser/net/predictor.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/common/frame_navigate_params.h"
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(chrome_browser_net::PredictorTabHelper);
+
+namespace {
+
+bool IsUserLinkNavigationRequest(content::PageTransition page_transition) {
+  bool isLink = (content::PageTransitionStripQualifier(page_transition) ==
+                 content::PAGE_TRANSITION_LINK);
+  bool isForwardBack = (page_transition &
+                        content::PAGE_TRANSITION_FORWARD_BACK);
+  bool isPrerender = (page_transition &
+                      content::PAGE_TRANSITION_PRERENDER);
+  // tracking navigation session including client-side redirect
+  // is currently not supported

[jar (doing other things), 2013/08/01 22:56:47]

nit: Start with upper case letter... and with period.

[kouhei (in TOK), 2013/08/02 06:18:03]

Done.

+  bool isClientRedirect = (page_transition &
+                           content::PAGE_TRANSITION_CLIENT_REDIRECT);
+  return isLink && !isForwardBack && !isPrerender && !isClientRedirect;
+}
+
+}  // namespace
+
+namespace chrome_browser_net {
+
+PredictorTabHelper::PredictorTabHelper(
+    content::WebContents* web_contents)

[jar (doing other things), 2013/08/01 22:56:47]

nit: no need to wrap

[kouhei (in TOK), 2013/08/02 06:18:03]

Done.

+    : content::WebContentsObserver(web_contents) {
+}
+
+PredictorTabHelper::~PredictorTabHelper() {
+}
+
+void PredictorTabHelper::DidNavigateMainFrame(
+    const content::LoadCommittedDetails& details,
+    const content::FrameNavigateParams& params) {
+  if (!IsUserLinkNavigationRequest(params.transition) ||
+      !(params.url.SchemeIs("http") || params.url.SchemeIs("https")))
+    return;
+
+  Profile* profile = Profile::FromBrowserContext(
+      web_contents()->GetBrowserContext());
+  profile->GetNetworkPredictor()->RecordLinkNavigation(params.url);
+}
+
+}  // namespace chrome_browser_net