Prevent tracking metrics for cases such as 204s and downloads.

chrome/browser/page_load_metrics/metrics_web_contents_observer.cc

 // Copyright 2015 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/page_load_metrics/metrics_web_contents_observer.h"
 
 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utility>
@@ skipping 830 matching lines @@
       std::move(provisional_loads_[navigation_handle]));
   provisional_loads_.erase(navigation_handle);
 
   // Ignore same-page navigations.
   if (navigation_handle->HasCommitted() && navigation_handle->IsSamePage()) {
     if (finished_nav)
       finished_nav->StopTracking();
     return;
   }
 
+  // Ignore internally generated aborts for navigations with HTTP responses that
+  // don't commit, such as HTTP 204 responses and downloads.
+  if (!navigation_handle->HasCommitted() &&
+      navigation_handle->GetNetErrorCode() == net::ERR_ABORTED &&
+      navigation_handle->GetResponseHeaders()) {
+    if (finished_nav)
+      finished_nav->StopTracking();
+    return;
+  }
+
   const bool should_track =
       finished_nav && ShouldTrackNavigation(navigation_handle);
 
   if (finished_nav && !should_track)
     finished_nav->StopTracking();
 
   if (navigation_handle->HasCommitted()) {
     // Notify other loads that they may have been aborted by this committed
     // load. is_certainly_browser_timestamp is set to false because
     // NavigationStart() could be set in either the renderer or browser process.
     NotifyAbortAllLoadsWithTimestamp(
         AbortTypeForPageTransition(navigation_handle->GetPageTransition()),
         IsNavigationUserInitiated(navigation_handle),
         navigation_handle->NavigationStart(), false);
 
     if (should_track) {
       HandleCommittedNavigationForTrackedLoad(navigation_handle,
                                               std::move(finished_nav));
     } else {
       committed_load_.reset();
     }
   } else if (should_track) {
     HandleFailedNavigationForTrackedLoad(navigation_handle,
                                          std::move(finished_nav));
   }
 }
 
 // Handle a pre-commit error. Navigations that result in an error page will be
-// ignored. Note that downloads/204s will result in HasCommitted() returning
-// false.
-// TODO(csharrison): Track changes to NavigationHandle for signals when this is
-// the case (HTTP response headers).
+// ignored.
 void MetricsWebContentsObserver::HandleFailedNavigationForTrackedLoad(
     content::NavigationHandle* navigation_handle,
     std::unique_ptr<PageLoadTracker> tracker) {
   tracker->FailedProvisionalLoad(navigation_handle);
 
   net::Error error = navigation_handle->GetNetErrorCode();
 
   // net::OK: This case occurs when the NavigationHandle finishes and reports
   // !HasCommitted(), but reports no net::Error. This should not occur
   // pre-PlzNavigate, but afterwards it should represent the navigation stopped
   // by the user before it was ready to commit.
   // net::ERR_ABORTED: An aborted provisional load has error
-  // net::ERR_ABORTED. Note that this can come from some non user-initiated
-  // errors, such as downloads, or 204 responses. See crbug.com/542369.
+  // net::ERR_ABORTED.
   if ((error == net::OK) || (error == net::ERR_ABORTED)) {
     tracker->NotifyAbort(ABORT_OTHER, false, base::TimeTicks::Now(), true);
     aborted_provisional_loads_.push_back(std::move(tracker));
   }
 }
 
 void MetricsWebContentsObserver::HandleCommittedNavigationForTrackedLoad(
     content::NavigationHandle* navigation_handle,
     std::unique_ptr<PageLoadTracker> tracker) {
   if (!navigation_handle->HasUserGesture() &&
@@ skipping 185 matching lines @@
     content::NavigationHandle* navigation_handle) const {
   DCHECK(navigation_handle->IsInMainFrame());
   DCHECK(!navigation_handle->HasCommitted() ||
          !navigation_handle->IsSamePage());
 
   return BrowserPageTrackDecider(embedder_interface_.get(), web_contents(),
                                  navigation_handle).ShouldTrack();
 }
 
 }  // namespace page_load_metrics