Log to UMA when x-origin frames (1) are created and (2) become visible

third_party/WebKit/Source/core/frame/LocalFrame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 51 matching lines @@
 #include "core/page/ChromeClient.h"
 #include "core/page/FocusController.h"
 #include "core/page/Page.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/paint/ObjectPainter.h"
 #include "core/paint/PaintInfo.h"
 #include "core/paint/PaintLayer.h"
 #include "core/paint/TransformRecorder.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "platform/DragImage.h"
+#include "platform/Histogram.h"
 #include "platform/JSONValues.h"
 #include "platform/PluginScriptForbiddenScope.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/StaticBitmapImage.h"
 #include "platform/graphics/paint/ClipRecorder.h"
 #include "platform/graphics/paint/PaintController.h"
 #include "platform/graphics/paint/SkPictureBuilder.h"
 #include "platform/graphics/paint/TransformDisplayItem.h"
@@ skipping 128 matching lines @@
 }
 
 inline float parentTextZoomFactor(LocalFrame* frame)
 {
     Frame* parent = frame->tree().parent();
     if (!parent || !parent->isLocalFrame())
         return 1;
     return toLocalFrame(parent)->textZoomFactor();
 }
 
+// These are logged to UMA, so don't re-arrange them without creating a new histogram.
+enum FrameStateForDeferredLoading {
+    Created,
+    WouldLoadBecauseVisible,
+    // TODO(dgrogan): Add WouldLoadBecauseTopOrLeft, WouldLoadBecauseDisplayNone, etc
+
+    FrameStateForDeferredLoadingEnd
+};
+
+void RecordStateToHistogram(FrameStateForDeferredLoading state)
+{
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, unseenFrameHistogram, ("FrameLoading.Deferred.StateCountsV1", FrameStateForDeferredLoadingEnd));
+    unseenFrameHistogram.count(state);
+}
+
 } // namespace
 
 template class CORE_TEMPLATE_EXPORT Supplement<LocalFrame>;
 
 LocalFrame* LocalFrame::create(FrameLoaderClient* client, FrameHost* host, FrameOwner* owner, InterfaceProvider* interfaceProvider)
 {
     LocalFrame* frame = new LocalFrame(client, host, owner, interfaceProvider ? interfaceProvider : InterfaceProvider::getEmptyInterfaceProvider());
     InspectorInstrumentation::frameAttachedToParent(frame);
     return frame;
 }
@@ skipping 569 matching lines @@
     , m_spellChecker(SpellChecker::create(*this))
     , m_selection(FrameSelection::create(this))
     , m_eventHandler(new EventHandler(this))
     , m_console(FrameConsole::create(*this))
     , m_inputMethodController(InputMethodController::create(*this))
     , m_navigationDisableCount(0)
     , m_pageZoomFactor(parentPageZoomFactor(this))
     , m_textZoomFactor(parentTextZoomFactor(this))
     , m_inViewSourceMode(false)
     , m_interfaceProvider(interfaceProvider)
+    , m_visibilityWasLogged(false)
+    , m_creationWasLogged(false)
 {
     if (isLocalRoot())
         m_instrumentingAgents = new InstrumentingAgents();
     else
         m_instrumentingAgents = localFrameRoot()->m_instrumentingAgents;
 }
 
 WebFrameScheduler* LocalFrame::frameScheduler()
 {
     return m_frameScheduler.get();
@@ skipping 11 matching lines @@
     return static_cast<FrameLoaderClient*>(Frame::client());
 }
 
 PluginData* LocalFrame::pluginData() const
 {
     if (!loader().allowPlugins(NotAboutToInstantiatePlugin))
         return nullptr;
     return page()->pluginData();
 }
 
+void LocalFrame::didInstallNewDocument()
+{
+    if (!m_creationWasLogged && isCrossOriginSubframe()) {

[dgrogan, 2016/08/19 23:56:23]

installNewDocument is called twice when an iframe is first created (at least
when it is created with a srcdoc) so I had to keep
LocalFrame::m_creationWasLogged, but the current solution is still better than
having to check m_creationWasLogged every time the visibility might have
changed.

[dcheng, 2016/08/22 07:00:29]

When a frame is first created, it always starts on the initial empty document
(https://html.spec.whatwg.org/multipage/browsers.html#initialise-the-document-...
kind of references this). So what happens is the initial empty document is
created and installed first, then the Document for the srcdoc is created and
installed.

Can we use FrameLoaderStateMachine::creatingInitialEmptyDocument() or
isDisplayingInitialEmptyDocument() to distinguish between these cases? I'm
guessing we don't want to record the UMA for the initial empty document.

[dgrogan, 2016/08/22 23:38:09]

You're right. This function is now only called when
committedFirstRealDocumentLoad() is true.

+        m_creationWasLogged = true;
+        RecordStateToHistogram(Created);
+    }
+}
+
+void LocalFrame::onVisibilityMaybeChanged(bool visible)
+{
+    if (visible && !m_visibilityWasLogged && isCrossOriginSubframe()) {
+        DCHECK(m_creationWasLogged);

[dgrogan, 2016/08/22 23:38:09]

This was racy.

+        m_visibilityWasLogged = true;
+        RecordStateToHistogram(WouldLoadBecauseVisible);
+    }
+}
+
 DEFINE_WEAK_IDENTIFIER_MAP(LocalFrame);
 
 FrameNavigationDisabler::FrameNavigationDisabler(LocalFrame& frame)
     : m_frame(&frame)
 {
     m_frame->disableNavigation();
 }
 
 FrameNavigationDisabler::~FrameNavigationDisabler()
 {
     m_frame->enableNavigation();
 }
 
 ScopedFrameBlamer::ScopedFrameBlamer(LocalFrame* frame)
     : m_frame(frame)
 {
     if (m_frame && m_frame->client() && m_frame->client()->frameBlameContext())
         m_frame->client()->frameBlameContext()->Enter();
 }
 
 ScopedFrameBlamer::~ScopedFrameBlamer()
 {
     if (m_frame && m_frame->client() && m_frame->client()->frameBlameContext())
         m_frame->client()->frameBlameContext()->Leave();
 }
 
 } // namespace blink