[Sessions] Add detailed logging of SessionRestore events.

content/browser/frame_host/navigation_controller_impl.cc

 // Copyright 2013 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 "content/browser/frame_host/navigation_controller_impl.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ skipping 17 matching lines @@
 #include "content/common/frame_messages.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/invalidate_type.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_widget_host.h"
 #include "content/public/browser/render_widget_host_view.h"
+#include "content/public/browser/session_restore_uma.h"
 #include "content/public/browser/storage_partition.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/common/content_switches.h"
 #include "net/base/escape.h"
 #include "net/base/mime_util.h"
 #include "net/base/net_util.h"
 #include "skia/ext/platform_canvas.h"
 #include "url/url_constants.h"
@@ skipping 1695 matching lines @@
 }
 
 // static
 size_t NavigationControllerImpl::max_entry_count() {
   if (max_entry_count_for_testing_ != kMaxEntryCountForTestingNotSet)
      return max_entry_count_for_testing_;
   return kMaxSessionHistoryEntries;
 }
 
 void NavigationControllerImpl::SetActive(bool is_active) {
-  if (is_active && needs_reload_)
+  if (is_active && needs_reload_) {
+    // If the pending navigation is a session restore entry then it is being
+    // loaded because of user action, and not automatically by the TabLoader.
+    // Consider this a deferred reload that the user then forced to occur.
+    // Better session restore tab prioritization should reduce the number of
+    // times this occurs.
+    NavigationEntryImpl* pending_entry =
+        entries_[last_committed_entry_index_].get();
+    if (pending_entry->restore_type() == RESTORE_LAST_SESSION_EXITED_CLEANLY ||
+        pending_entry->restore_type() == RESTORE_LAST_SESSION_CRASHED) {
+      UMA_HISTOGRAM_ENUMERATION(
+          content::kSessionRestoreTabActions,
+          content::kSessionRestoreTabActionsUma_DeferredTabLoadedByUserAction,
+          content::kSessionRestoreTabActionsUma_Max);
+    }
+
     LoadIfNecessary();
+  }
 }
 
 void NavigationControllerImpl::LoadIfNecessary() {
   if (!needs_reload_)
     return;
 
   // Calling Reload() results in ignoring state, and not loading.
   // Explicitly use NavigateToPendingEntry so that the renderer uses the
   // cached state.
   pending_entry_index_ = last_committed_entry_index_;
@@ skipping 102 matching lines @@
     }
   }
 }
 
 void NavigationControllerImpl::SetGetTimestampCallbackForTest(
     const base::Callback<base::Time()>& get_timestamp_callback) {
   get_timestamp_callback_ = get_timestamp_callback;
 }
 
 }  // namespace content