Add support for counting same-document AMP loads.

chrome/browser/page_load_metrics/page_load_tracker.cc

 // Copyright 2016 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/page_load_tracker.h"
 
 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utility>
@@ skipping 533 matching lines @@
   user_initiated_info_.user_gesture = navigation_handle->HasUserGesture();
 
   INVOKE_AND_PRUNE_OBSERVERS(
       observers_, ShouldObserveMimeType,
       navigation_handle->GetWebContents()->GetContentsMimeType());
 
   INVOKE_AND_PRUNE_OBSERVERS(observers_, OnCommit, navigation_handle);
   LogAbortChainHistograms(navigation_handle);
 }
 
+void PageLoadTracker::DidCommitSameDocumentNavigation(
+    content::NavigationHandle* navigation_handle) {
+  for (const auto& observer : observers_) {
+    observer->OnCommitSameDocumentNavigation(navigation_handle);
+  }
+}
+
 void PageLoadTracker::DidFinishSubFrameNavigation(
     content::NavigationHandle* navigation_handle) {
-  INVOKE_AND_PRUNE_OBSERVERS(observers_, OnDidFinishSubFrameNavigation,
-                             navigation_handle);
+  for (const auto& observer : observers_) {
+    observer->OnDidFinishSubFrameNavigation(navigation_handle);
+  }
 
   if (!navigation_handle->HasCommitted())
     return;
 
   // We have a new committed navigation, so discard information about the
   // previously committed navigation.
   subframe_navigation_start_offset_.erase(
       navigation_handle->GetFrameTreeNodeId());
 
   BrowserPageTrackDecider decider(embedder_interface_,
@@ skipping 368 matching lines @@
     observer->MediaStartedPlaying(video_type, is_in_main_frame);
 }
 
 void PageLoadTracker::OnNavigationDelayComplete(base::TimeDelta scheduled_delay,
                                                 base::TimeDelta actual_delay) {
   for (const auto& observer : observers_)
     observer->OnNavigationDelayComplete(scheduled_delay, actual_delay);
 }
 
 }  // namespace page_load_metrics