Record UMA stats for subframes history navigations.

content/browser/frame_host/navigator_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/navigator_impl.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/strings/string_util.h"
 #include "base/time/time.h"
 #include "content/browser/frame_host/debug_urls.h"
 #include "content/browser/frame_host/frame_tree.h"
 #include "content/browser/frame_host/frame_tree_node.h"
 #include "content/browser/frame_host/navigation_controller_impl.h"
 #include "content/browser/frame_host/navigation_entry_impl.h"
 #include "content/browser/frame_host/navigation_handle_impl.h"
 #include "content/browser/frame_host/navigation_request.h"
 #include "content/browser/frame_host/navigation_request_info.h"
 #include "content/browser/frame_host/navigator_delegate.h"
@@ skipping 416 matching lines @@
     FrameTreeNode* frame_tree_node,
     const FrameNavigationEntry& frame_entry,
     ReloadType reload_type,
     bool is_same_document_history_load) {
   return NavigateToEntry(frame_tree_node, frame_entry,
                          *controller_->GetPendingEntry(), reload_type,
                          is_same_document_history_load, false, true, nullptr);
 }
 
 bool NavigatorImpl::NavigateNewChildFrame(
-    RenderFrameHostImpl* render_frame_host) {
+    RenderFrameHostImpl* render_frame_host,
+    const GURL& default_url) {
   NavigationEntryImpl* entry =
       controller_->GetEntryWithUniqueID(render_frame_host->nav_entry_id());
   if (!entry)
     return false;
 
   FrameNavigationEntry* frame_entry =
       entry->GetFrameEntry(render_frame_host->frame_tree_node());
   if (!frame_entry)
     return false;
 
+  // Track how often history navigations load a different URL into a subframe
+  // than the frame's default URL.
+  bool restoring_different_url = frame_entry->url() != default_url;
+  UMA_HISTOGRAM_BOOLEAN("SessionRestore.RestoredSubframeURL",
+                        restoring_different_url);
+  // If this frame's unique name uses a frame path, record the name length.
+  // If these names are long in practice, then a proposed plan to truncate
+  // unique names might affect restore behavior, since it is complex to deal
+  // with truncated names inside frame paths.
+  if (restoring_different_url) {
+    const std::string& unique_name =
+        render_frame_host->frame_tree_node()->unique_name();
+    const char kFramePathPrefix[] = "<!--framePath ";
+    if (base::StartsWith(unique_name, kFramePathPrefix,
+                         base::CompareCase::SENSITIVE)) {
+      UMA_HISTOGRAM_COUNTS("SessionRestore.RestoreSubframeFramePathLength",
+                           unique_name.size());
+    }
+  }
+
   return NavigateToEntry(render_frame_host->frame_tree_node(), *frame_entry,
                          *entry, ReloadType::NONE, false, true, false, nullptr);
 }
 
 void NavigatorImpl::DidNavigate(
     RenderFrameHostImpl* render_frame_host,
     const FrameHostMsg_DidCommitProvisionalLoad_Params& params) {
   FrameTree* frame_tree = render_frame_host->frame_tree_node()->frame_tree();
   bool oopifs_possible = SiteIsolationPolicy::AreCrossProcessFramesPossible();
 
@@ skipping 733 matching lines @@
     if (navigation_handle)
       navigation_handle->update_entry_id_for_transfer(entry->GetUniqueID());
 
     controller_->SetPendingEntry(std::move(entry));
     if (delegate_)
       delegate_->NotifyChangedNavigationState(content::INVALIDATE_TYPE_URL);
   }
 }
 
 }  // namespace content