Measure the number of frame loads with Flash.

content/browser/web_contents/web_contents_impl.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 "content/browser/web_contents/web_contents_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 2728 matching lines @@
   //   future arrives, update this code to not allow this case.
   DCHECK_GE(loading_frames_in_progress_, 0);
   if (loading_progresses_.find(render_frame_id) == loading_progresses_.end()) {
     if (loading_frames_in_progress_ == 0)
       DidStartLoading(rfh, to_different_document);
     ++loading_frames_in_progress_;
   }
 
   loading_progresses_[render_frame_id] = kMinimumLoadingProgress;
   SendLoadProgressChanged();
+  RecordAction(base::UserMetricsAction("FrameLoad"));

[Charlie Reis, 2014/10/31 16:55:45]

DidStartLoading isn't the right place for this-- the navigation could fail.

I'm surprised if we don't have something like this already.  If not, we should
probably watch for it at commit time, similar to
NavigatorImpl::RecordNavigationMetrics.  I'm guessing you also don't want to
count in-page navigations, but I'm not sure.

[Lei Zhang, 2014/11/01 00:51:47]

FWIW, the PageLoad metric that's used as part of "NN foo per million page loads"
also doesn't care about failed navigation and navigation to anchors. But I agree
it's odd.

Successful, not in-page frame loads seem more accurate, so that's what I tried
to do.

 }
 
 void WebContentsImpl::OnDidStopLoading() {
   RenderFrameHostImpl* rfh =
       static_cast<RenderFrameHostImpl*>(render_frame_message_source_);
   int64 render_frame_id = rfh->frame_tree_node()->frame_tree_node_id();
 
   if (loading_progresses_.find(render_frame_id) != loading_progresses_.end()) {
     // Load stopped while we were still tracking load.  Make sure we update
     // progress based on this frame's completion.
@@ skipping 1572 matching lines @@
   node->render_manager()->ResumeResponseDeferredAtStart();
 }
 
 void WebContentsImpl::SetForceDisableOverscrollContent(bool force_disable) {
   force_disable_overscroll_content_ = force_disable;
   if (view_)
     view_->SetOverscrollControllerEnabled(CanOverscrollContent());
 }
 
 }  // namespace content