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/browser/notification_details.h"
+#include "content/public/browser/notification_source.h"
+#include "content/public/browser/notification_types.h"
+#include "content/public/browser/resource_request_details.h"
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(chrome_browser_net::PredictorTabHelper);
+
+namespace {
+
+bool IsUserLinkNavigationRequest(content::ResourceRequestDetails* details) {
+  if (details->resource_type != ResourceType::MAIN_FRAME)
+    return false;
+
+  content::PageTransition page_transition = details->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
+  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)
+    : web_contents_(web_contents) {
+  registrar_.Add(this,
+                 content::NOTIFICATION_RESOURCE_RESPONSE_STARTED,
+                 content::Source<content::WebContents>(web_contents));
+  registrar_.Add(this,
+                 content::NOTIFICATION_RESOURCE_RECEIVED_REDIRECT,
+                 content::Source<content::WebContents>(web_contents));
+}
+
+PredictorTabHelper::~PredictorTabHelper() {
+}
+
+void PredictorTabHelper::Observe(int type,
+             const content::NotificationSource& source,
+             const content::NotificationDetails& details) {
+  switch (type) {
+    case content::NOTIFICATION_RESOURCE_RESPONSE_STARTED: {
+      content::ResourceRequestDetails* resource_request_details =
+          content::Details<content::ResourceRequestDetails>(details).ptr();
+      if (IsUserLinkNavigationRequest(resource_request_details)) {
+        DidNavigation(resource_request_details->url,
+                      resource_request_details->original_url);
+      }
+      break;
+    }
+    case content::NOTIFICATION_RESOURCE_RECEIVED_REDIRECT: {
+      content::ResourceRedirectDetails* resource_redirect_details =
+          content::Details<content::ResourceRedirectDetails>(details).ptr();
+      if (IsUserLinkNavigationRequest(resource_redirect_details)) {
+        DidNavigation(resource_redirect_details->url,
+                      resource_redirect_details->original_url);
+      }
+      break;
+    }
+    default:
+      NOTREACHED();
+  }
+}
+
+void PredictorTabHelper::DidNavigation(const GURL& url,
+                                       const GURL& original_url) {
+  if (!url.SchemeIs("http") && !url.SchemeIs("https"))
+    return;
+
+  Profile* profile = Profile::FromBrowserContext(
+      web_contents_->GetBrowserContext());
+  profile->GetNetworkPredictor()->RecordPreconnectNavigationStat(
+      url, original_url);
+}
+
+}  // namespace chrome_browser_net