Report frequency of single page app navigations to UMA

third_party/WebKit/Source/core/loader/FrameLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) Research In Motion Limited 2009. All rights reserved.
  * Copyright (C) 2011 Kris Jordan <krisjordan@gmail.com>
  * Copyright (C) 2011 Google Inc. All rights reserved.
@@ skipping 61 matching lines @@
 #include "core/loader/ProgressTracker.h"
 #include "core/loader/appcache/ApplicationCacheHost.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/CreateWindow.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/probe/CoreProbes.h"
 #include "core/svg/graphics/SVGImage.h"
 #include "core/xml/parser/XMLDocumentParser.h"
+#include "platform/Histogram.h"
 #include "platform/InstanceCounters.h"
 #include "platform/PluginScriptForbiddenScope.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/bindings/DOMWrapperWorld.h"
 #include "platform/instrumentation/tracing/TraceEvent.h"
 #include "platform/loader/fetch/ResourceFetcher.h"
 #include "platform/loader/fetch/ResourceRequest.h"
 #include "platform/network/HTTPParsers.h"
 #include "platform/network/NetworkUtils.h"
 #include "platform/scroll/ScrollAnimatorBase.h"
@@ skipping 385 matching lines @@
   return allowed;
 }
 
 void FrameLoader::UpdateForSameDocumentNavigation(
     const KURL& new_url,
     SameDocumentNavigationSource same_document_navigation_source,
     PassRefPtr<SerializedScriptValue> data,
     HistoryScrollRestorationType scroll_restoration_type,
     FrameLoadType type,
     Document* initiating_document) {
+  UMA_HISTOGRAM_ENUMERATION(
+      "RendererScheduler.UpdateForSameDocumentNavigationCount", type,
+      FrameLoadType::kFrameLoadTypeCount);

[Nate Chapin, 2017/06/14 18:10:50]

FrameLoadTypes might be overloaded. For example, FrameLoadTypeStandard could be
a fragment navigation that adds a history entry, or it could result from a
history.pushState() JS call. Do you want to split those down further?

Or more generally: What are you trying to accomplish with this data? It's not
clear to me what you want to learn from this histogram.

[tdresser, 2017/06/14 18:30:52]

Great question.

The high level question we want to answer is "approximately what fraction of
navigations are within-app navigations."

We just want an approximation, so we figured just counting the number of same
single page app navigations, and comparing to a separate page load metric would
be good enough. 

Since there was already a convenient enum lying around to figure out where same
document navigations were coming from, we figured we might as well split by that
enum.

We could probably also get away with just recording the total number of
navigations with a load type of:
- kStandard
- kReplaceCurrentItem

Does that sound about right? I don't have a ton of context in this space, let us
know if we're completely off base here.

[Liquan (Max) Gu, 2017/06/20 23:35:39]

Done.

   TRACE_EVENT1("blink", "FrameLoader::updateForSameDocumentNavigation", "url",
                new_url.GetString().Ascii().data());
 
   // Generate start and stop notifications only when loader is completed so that
   // we don't fire them for fragment redirection that happens in window.onload
   // handler. See https://bugs.webkit.org/show_bug.cgi?id=31838
   // Do not fire the notifications if the frame is concurrently navigating away
   // from the document, since a new document is already loading.
   if (frame_->GetDocument()->LoadEventFinished() &&
       !provisional_document_loader_)
@@ skipping 1187 matching lines @@
   // TODO(japhet): This is needed because the browser process DCHECKs if the
   // first entry we commit in a new frame has replacement set. It's unclear
   // whether the DCHECK is right, investigate removing this special case.
   bool replace_current_item = load_type == kFrameLoadTypeReplaceCurrentItem &&
                               (!Opener() || !request.Url().IsEmpty());
   loader->SetReplacesCurrentHistoryItem(replace_current_item);
   return loader;
 }
 
 }  // namespace blink