Bug 1750034 - Remove lazyload telemetry related code r=emilio

We have decided to use 600px in all directions, there's no need
to keep the telemetry stuff around.

Differential Revision: https://phabricator.services.mozilla.com/D155879

browser/base/content/browser.js

@@ -6066,15 +6066,6 @@ var TabsProgressListener = {
           stopwatchRunning /* we won't see STATE_START events for pre-rendered tabs */
         ) {
           if (recordLoadTelemetry) {
-            if (aBrowser.browsingContext?.topWindowContext?.hadLazyLoadImage) {
-              let timeElapsed = TelemetryStopwatch.timeElapsed(
-                histogram,
-                aBrowser
-              );
-              Services.telemetry
-                .getHistogramById("FX_LAZYLOAD_IMAGE_PAGE_LOAD_MS")
-                .add(timeElapsed);
-            }
             TelemetryStopwatch.finish(histogram, aBrowser);
             BrowserTelemetryUtils.recordSiteOriginTelemetry(browserWindows());
           }

docshell/base/WindowContext.cpp

@@ -284,11 +284,6 @@ bool WindowContext::CanSet(FieldIndex<IDX_IsLocalIP>, const bool& aValue,
   return CheckOnlyOwningProcessCanSet(aSource);
 }
 
-bool WindowContext::CanSet(FieldIndex<IDX_HadLazyLoadImage>, const bool& aValue,
-                           ContentParent* aSource) {
-  return IsTop();
-}
-
 bool WindowContext::CanSet(FieldIndex<IDX_AllowJavascript>, bool aValue,
                            ContentParent* aSource) {
   return (XRE_IsParentProcess() && !aSource) ||

docshell/base/WindowContext.h

@@ -85,9 +85,6 @@ class BrowsingContextGroup;
   /* Whether the principal of this window is for a local                 \
    * IP address */                                                       \
   FIELD(IsLocalIP, bool)                                                 \
-  /* Whether the corresponding document has `loading='lazy'`             \
-   * images; It won't become false if the image becomes non-lazy */      \
-  FIELD(HadLazyLoadImage, bool)                                          \
   /* Whether any of the windows in the subtree rooted at this window has \
    * active peer connections or not (only set on the top window). */     \
   FIELD(HasActivePeerConnections, bool)                                  \
@@ -205,8 +202,6 @@ class WindowContext : public nsISupports, public nsWrapperCache {
 
   bool CanShowPopup();
 
-  bool HadLazyLoadImage() const { return GetHadLazyLoadImage(); }
-
   bool AllowJavascript() const { return GetAllowJavascript(); }
   bool CanExecuteScripts() const { return mCanExecuteScripts; }
 
@@ -302,9 +297,6 @@ class WindowContext : public nsISupports, public nsWrapperCache {
   bool CanSet(FieldIndex<IDX_IsLocalIP>, const bool& aValue,
               ContentParent* aSource);
 
-  bool CanSet(FieldIndex<IDX_HadLazyLoadImage>, const bool& aValue,
-              ContentParent* aSource);
-
   bool CanSet(FieldIndex<IDX_AllowJavascript>, bool aValue,
               ContentParent* aSource);
   void DidSet(FieldIndex<IDX_AllowJavascript>, bool aOldValue);

dom/base/DOMIntersectionObserver.cpp

@@ -145,19 +145,7 @@ static void LazyLoadCallback(
     MOZ_ASSERT(entry->Target()->IsHTMLElement(nsGkAtoms::img));
     if (entry->IsIntersecting()) {
       static_cast<HTMLImageElement*>(entry->Target())
-          ->StopLazyLoading(HTMLImageElement::FromIntersectionObserver::Yes,
+          ->StopLazyLoading(HTMLImageElement::StartLoading::Yes);
-                            HTMLImageElement::StartLoading::Yes);
-    }
-  }
-}
-
-static void LazyLoadCallbackReachViewport(
-    const Sequence<OwningNonNull<DOMIntersectionObserverEntry>>& aEntries) {
-  for (const auto& entry : aEntries) {
-    MOZ_ASSERT(entry->Target()->IsHTMLElement(nsGkAtoms::img));
-    if (entry->IsIntersecting()) {
-      static_cast<HTMLImageElement*>(entry->Target())
-          ->LazyLoadImageReachedViewport();
     }
   }
 }
@@ -194,14 +182,6 @@ DOMIntersectionObserver::CreateLazyLoadObserver(Document& aDocument) {
   return observer.forget();
 }
 
-already_AddRefed<DOMIntersectionObserver>
-DOMIntersectionObserver::CreateLazyLoadObserverViewport(Document& aDocument) {
-  RefPtr<DOMIntersectionObserver> observer =
-      new DOMIntersectionObserver(aDocument, LazyLoadCallbackReachViewport);
-  observer->mThresholds.AppendElement(0.0f);
-  return observer.forget();
-}
-
 bool DOMIntersectionObserver::SetRootMargin(const nsACString& aString) {
   return Servo_IntersectionObserverRootMargin_Parse(&aString, &mRootMargin);
 }

dom/base/Document.cpp

@@ -1404,10 +1404,6 @@ Document::Document(const char* aContentType)
       mXMLDeclarationBits(0),
       mOnloadBlockCount(0),
       mWriteLevel(0),
-      mLazyLoadImageCount(0),
-      mLazyLoadImageStarted(0),
-      mLazyLoadImageReachViewportLoading(0),
-      mLazyLoadImageReachViewportLoaded(0),
       mContentEditableCount(0),
       mEditingState(EditingState::eOff),
       mCompatMode(eCompatibility_FullStandards),
@@ -15617,25 +15613,6 @@ void Document::ReportDocumentUseCounters() {
             (" > %s\n", Telemetry::GetHistogramName(id)));
     Telemetry::Accumulate(id, 1);
   }
-
-  ReportDocumentLazyLoadCounters();
-}
-
-void Document::ReportDocumentLazyLoadCounters() {
-  if (!mLazyLoadImageCount) {
-    return;
-  }
-  Telemetry::Accumulate(Telemetry::LAZYLOAD_IMAGE_TOTAL, mLazyLoadImageCount);
-  Telemetry::Accumulate(Telemetry::LAZYLOAD_IMAGE_STARTED,
-                        mLazyLoadImageStarted);
-  Telemetry::Accumulate(Telemetry::LAZYLOAD_IMAGE_NOT_VIEWPORT,
-                        mLazyLoadImageStarted -
-                            mLazyLoadImageReachViewportLoading -
-                            mLazyLoadImageReachViewportLoaded);
-  Telemetry::Accumulate(Telemetry::LAZYLOAD_IMAGE_VIEWPORT_LOADING,
-                        mLazyLoadImageReachViewportLoading);
-  Telemetry::Accumulate(Telemetry::LAZYLOAD_IMAGE_VIEWPORT_LOADED,
-                        mLazyLoadImageReachViewportLoaded);
 }
 
 void Document::SendPageUseCounters() {
@@ -15752,22 +15729,6 @@ DOMIntersectionObserver& Document::EnsureLazyLoadImageObserver() {
   return *mLazyLoadImageObserver;
 }
 
-DOMIntersectionObserver& Document::EnsureLazyLoadImageObserverViewport() {
-  if (!mLazyLoadImageObserverViewport) {
-    mLazyLoadImageObserverViewport =
-        DOMIntersectionObserver::CreateLazyLoadObserverViewport(*this);
-  }
-  return *mLazyLoadImageObserverViewport;
-}
-
-void Document::IncLazyLoadImageReachViewport(bool aLoading) {
-  if (aLoading) {
-    ++mLazyLoadImageReachViewportLoading;
-  } else {
-    ++mLazyLoadImageReachViewportLoaded;
-  }
-}
-
 ResizeObserver& Document::EnsureLastRememberedSizeObserver() {
   if (!mLastRememberedSizeObserver) {
     mLastRememberedSizeObserver =
@@ -16158,17 +16119,6 @@ bool Document::ConsumeTransientUserGestureActivation() {
   return wc && wc->ConsumeTransientUserGestureActivation();
 }
 
-void Document::IncLazyLoadImageCount() {
-  if (!mLazyLoadImageCount) {
-    if (WindowContext* wc = GetTopLevelWindowContext()) {
-      if (!wc->HadLazyLoadImage()) {
-        Unused << wc->SetHadLazyLoadImage(true);
-      }
-    }
-  }
-  ++mLazyLoadImageCount;
-}
-
 void Document::SetDocTreeHadMedia() {
   RefPtr<WindowContext> topWc = GetTopLevelWindowContext();
   if (topWc && !topWc->IsDiscarded() && !topWc->GetDocTreeHadMedia()) {

dom/base/Document.h

@@ -3747,14 +3747,6 @@ class Document : public nsINode,
     return mLazyLoadImageObserverViewport;
   }
   DOMIntersectionObserver& EnsureLazyLoadImageObserver();
-  DOMIntersectionObserver& EnsureLazyLoadImageObserverViewport();
-  void IncLazyLoadImageCount();
-  void DecLazyLoadImageCount() {
-    MOZ_DIAGNOSTIC_ASSERT(mLazyLoadImageCount > 0);
-    --mLazyLoadImageCount;
-  }
-  void IncLazyLoadImageStarted() { ++mLazyLoadImageStarted; }
-  void IncLazyLoadImageReachViewport(bool aLoading);
 
   ResizeObserver* GetLastRememberedSizeObserver() {
     return mLastRememberedSizeObserver;
@@ -4833,19 +4825,6 @@ class Document : public nsINode,
   // finishes processing that script.
   uint32_t mWriteLevel;
 
-  // The amount of images that have `loading="lazy"` on the page or have loaded
-  // lazily already.
-  uint32_t mLazyLoadImageCount;
-  // Number of lazy-loaded images that we've started loading as a result of
-  // triggering the lazy-load observer threshold.
-  uint32_t mLazyLoadImageStarted;
-  // Number of lazy-loaded images that reached the viewport which were not done
-  // loading when they did so.
-  uint32_t mLazyLoadImageReachViewportLoading;
-  // Number of lazy-loaded images that reached the viewport and were done
-  // loading when they did so.
-  uint32_t mLazyLoadImageReachViewportLoaded;
-
   uint32_t mContentEditableCount;
   EditingState mEditingState;
 

dom/chrome-webidl/WindowGlobalActors.webidl

@@ -33,10 +33,6 @@ interface WindowContext {
   // True if the principal of this window is for a local ip address.
   readonly attribute boolean isLocalIP;
 
-  // True if the corresponding document has `loading='lazy'` images;
-  // It won't become false if the image becomes non-lazy.
-  readonly attribute boolean hadLazyLoadImage;
-
   /**
    * Partially determines whether script execution is allowed in this
    * BrowsingContext. Script execution will be permitted only if this

dom/html/HTMLImageElement.cpp

@@ -347,7 +347,7 @@ nsresult HTMLImageElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
       SetLazyLoading();
     } else if (aOldValue &&
                Loading(aOldValue->GetEnumValue()) == Loading::Lazy) {
-      StopLazyLoading(FromIntersectionObserver::No, StartLoading::Yes);
+      StopLazyLoading(StartLoading::Yes);
     }
   } else if (aName == nsGkAtoms::src && !aValue) {
     // NOTE: regular src value changes are handled in AfterMaybeChangeAttr, so
@@ -662,7 +662,6 @@ void HTMLImageElement::NodeInfoChanged(Document* aOldDoc) {
 
   if (mLazyLoading) {
     aOldDoc->GetLazyLoadImageObserver()->Unobserve(*this);
-    aOldDoc->DecLazyLoadImageCount();
     mLazyLoading = false;
     SetLazyLoading();
   }
@@ -939,7 +938,7 @@ nsresult HTMLImageElement::LoadSelectedImage(bool aForce, bool aNotify,
                                           triggeringPrincipal, GetCORSMode())) {
       return NS_OK;
     }
-    StopLazyLoading(FromIntersectionObserver::No, StartLoading::No);
+    StopLazyLoading(StartLoading::No);
   }
 
   nsresult rv = NS_ERROR_FAILURE;
@@ -1298,8 +1297,6 @@ void HTMLImageElement::SetLazyLoading() {
   }
 
   doc->EnsureLazyLoadImageObserver().Observe(*this);
-  doc->EnsureLazyLoadImageObserverViewport().Observe(*this);
-  doc->IncLazyLoadImageCount();
   mLazyLoading = true;
   UpdateImageState(true);
 }
@@ -1320,9 +1317,7 @@ void HTMLImageElement::StartLoadingIfNeeded() {
   }
 }
 
-void HTMLImageElement::StopLazyLoading(
+void HTMLImageElement::StopLazyLoading(StartLoading aStartLoading) {
-    FromIntersectionObserver aFromIntersectionObserver,
-    StartLoading aStartLoading) {
   if (!mLazyLoading) {
     return;
   }
@@ -1332,28 +1327,11 @@ void HTMLImageElement::StopLazyLoading(
     obs->Unobserve(*this);
   }
 
-  if (bool(aFromIntersectionObserver)) {
-    doc->IncLazyLoadImageStarted();
-  } else {
-    doc->DecLazyLoadImageCount();
-    if (auto* obs = doc->GetLazyLoadImageObserverViewport()) {
-      obs->Unobserve(*this);
-    }
-  }
-
   if (bool(aStartLoading)) {
     StartLoadingIfNeeded();
   }
 }
 
-void HTMLImageElement::LazyLoadImageReachedViewport() {
-  Document* doc = OwnerDoc();
-  if (auto* obs = doc->GetLazyLoadImageObserverViewport()) {
-    obs->Unobserve(*this);
-  }
-  doc->IncLazyLoadImageReachViewport(!Complete());
-}
-
 const nsMappedAttributes* HTMLImageElement::GetMappedAttributesFromSource()
     const {
   if (!IsInPicture() || !mResponsiveSelector ||

dom/html/HTMLImageElement.h

@@ -266,9 +266,7 @@ class HTMLImageElement final : public nsGenericHTMLElement,
 
   enum class FromIntersectionObserver : bool { No, Yes };
   enum class StartLoading : bool { No, Yes };
-  void StopLazyLoading(FromIntersectionObserver, StartLoading);
+  void StopLazyLoading(StartLoading);
-
-  void LazyLoadImageReachedViewport();
 
   // This is used when restyling, for retrieving the extra style from the source
   // element.

layout/base/tests/browser.ini

@@ -30,11 +30,3 @@ skip-if =
 support-files =
   !/gfx/layers/apz/test/mochitest/apz_test_native_event_utils.js
   !/browser/base/content/test/forms/head.js
-[browser_lazyload_telemetry.js]
-support-files =
-  file_lazyload_telemetry.html
-  image_rgrg-256x256.png
-[browser_lazyload_page_load_telemetry_iframe.js]
-support-files =
-  file_lazyload_telemetry.html
-  image_rgrg-256x256.png

layout/base/tests/browser_lazyload_page_load_telemetry_iframe.js

@@ -1,48 +0,0 @@
-const baseURL = getRootDirectory(gTestPath).replace(
-  "chrome://mochitests/content",
-  "http://example.com"
-);
-
-const testFileURL = `${baseURL}file_lazyload_telemetry.html`;
-
-const { TelemetryTestUtils } = ChromeUtils.import(
-  "resource://testing-common/TelemetryTestUtils.jsm"
-);
-
-function OtherLazyLoadDataIsReported() {
-  const snapshot = Services.telemetry.getSnapshotForHistograms("main", false)
-    .content;
-  return snapshot.LAZYLOAD_IMAGE_TOTAL;
-}
-
-function pageLoadIsReported() {
-  const snapshot = Services.telemetry.getSnapshotForHistograms("main", false)
-    .parent;
-  return snapshot.FX_LAZYLOAD_IMAGE_PAGE_LOAD_MS;
-}
-
-add_task(async function testTelemetryCollection() {
-  Services.telemetry.getHistogramById("FX_LAZYLOAD_IMAGE_PAGE_LOAD_MS").clear();
-
-  const testTab = await BrowserTestUtils.openNewForegroundTab(
-    gBrowser,
-    "data:text/html,<body><iframe src='" + testFileURL + "'></iframe></body>",
-    true
-  );
-
-  await BrowserTestUtils.waitForCondition(pageLoadIsReported);
-
-  gBrowser.removeTab(testTab);
-
-  // Running this test also causes some other LAZYLOAD related data
-  // to be collected. Wait for them to be collected to avoid firing
-  // them at an unexpected time.
-  await BrowserTestUtils.waitForCondition(OtherLazyLoadDataIsReported);
-
-  const snapshot = Services.telemetry.getSnapshotForHistograms("main", false);
-
-  ok(
-    snapshot.parent.FX_LAZYLOAD_IMAGE_PAGE_LOAD_MS.sum > 0,
-    "lazyload image page load telemetry"
-  );
-});

layout/base/tests/browser_lazyload_telemetry.js

@@ -1,88 +0,0 @@
-const baseURL = getRootDirectory(gTestPath).replace(
-  "chrome://mochitests/content",
-  "http://example.com"
-);
-
-const testFileURL = `${baseURL}file_lazyload_telemetry.html`;
-
-const { TelemetryTestUtils } = ChromeUtils.import(
-  "resource://testing-common/TelemetryTestUtils.jsm"
-);
-
-function pageLoadIsReported() {
-  const snapshot = Services.telemetry.getSnapshotForHistograms("main", false)
-    .parent;
-  return snapshot.FX_LAZYLOAD_IMAGE_PAGE_LOAD_MS;
-}
-
-function dataIsReported() {
-  const snapshot = Services.telemetry.getSnapshotForHistograms("main", false)
-    .content;
-  return (
-    snapshot.LAZYLOAD_IMAGE_STARTED && snapshot.LAZYLOAD_IMAGE_STARTED.values[4]
-  );
-}
-
-add_task(async function testTelemetryCollection() {
-  Services.telemetry.getHistogramById("LAZYLOAD_IMAGE_TOTAL").clear();
-  Services.telemetry.getHistogramById("LAZYLOAD_IMAGE_STARTED").clear();
-  Services.telemetry.getHistogramById("LAZYLOAD_IMAGE_NOT_VIEWPORT").clear();
-  Services.telemetry
-    .getHistogramById("LAZYLOAD_IMAGE_VIEWPORT_LOADING")
-    .clear();
-  Services.telemetry.getHistogramById("LAZYLOAD_IMAGE_VIEWPORT_LOADED").clear();
-  Services.telemetry.getHistogramById("FX_LAZYLOAD_IMAGE_PAGE_LOAD_MS").clear();
-
-  const testTab = await BrowserTestUtils.openNewForegroundTab(
-    gBrowser,
-    testFileURL,
-    true
-  );
-
-  await SpecialPowers.spawn(
-    testTab.linkedBrowser.browsingContext,
-    [],
-    async () => {
-      const image2 = content.document.getElementById("image2");
-      image2.scrollIntoView();
-
-      await new Promise(resolve => {
-        content.requestAnimationFrame(() => {
-          content.requestAnimationFrame(resolve);
-        });
-      });
-    }
-  );
-
-  await BrowserTestUtils.waitForCondition(pageLoadIsReported);
-
-  gBrowser.removeTab(testTab);
-
-  await BrowserTestUtils.waitForCondition(dataIsReported);
-
-  const snapshot = Services.telemetry.getSnapshotForHistograms("main", false);
-
-  // Ensures we have 4 lazyload images.
-  is(snapshot.content.LAZYLOAD_IMAGE_TOTAL.values[4], 1, "total images");
-  // All 4 images should be lazy-loaded.
-  is(snapshot.content.LAZYLOAD_IMAGE_STARTED.values[4], 1, "started to load");
-  // The last image didn't reach to the viewport.
-  is(
-    snapshot.content.LAZYLOAD_IMAGE_NOT_VIEWPORT.values[1],
-    1,
-    "images didn't reach viewport"
-  );
-  // The sum of the images that reached to the viewport
-  // should be three. This includes all images except
-  // the last one.
-  is(
-    snapshot.content.LAZYLOAD_IMAGE_VIEWPORT_LOADING.sum +
-      snapshot.content.LAZYLOAD_IMAGE_VIEWPORT_LOADED.sum,
-    3,
-    "images reached viewport"
-  );
-  ok(
-    snapshot.parent.FX_LAZYLOAD_IMAGE_PAGE_LOAD_MS.sum > 0,
-    "lazyload image page load telemetry"
-  );
-});

toolkit/components/telemetry/Histograms.json

@@ -5479,66 +5479,6 @@
     "releaseChannelCollection": "opt-out",
     "description": "How long (sec) a tab had been unloaded until it was reloaded."
   },
-  "LAZYLOAD_IMAGE_TOTAL": {
-    "record_in_processes": ["main", "content"],
-    "products": ["firefox"],
-    "alert_emails": ["sefeng@mozilla.com"],
-    "bug_numbers": [1687358],
-    "expires_in_version": "never",
-    "kind": "exponential",
-    "high": 2000,
-    "n_buckets": 100,
-    "releaseChannelCollection": "opt-out",
-    "description": "The amount of images that have `loading='lazy'` on the page or have loaded lazily already."
-  },
-  "LAZYLOAD_IMAGE_STARTED": {
-    "record_in_processes": ["main", "content"],
-    "products": ["firefox"],
-    "alert_emails": ["sefeng@mozilla.com"],
-    "bug_numbers": [1687358],
-    "expires_in_version": "never",
-    "kind": "exponential",
-    "high": 2000,
-    "n_buckets": 100,
-    "releaseChannelCollection": "opt-out",
-    "description": "Number of lazy-loaded images that we've started loading as a result of triggering the lazy-load observer threshold."
-  },
-  "LAZYLOAD_IMAGE_NOT_VIEWPORT": {
-    "record_in_processes": ["main", "content"],
-    "products": ["firefox"],
-    "alert_emails": ["sefeng@mozilla.com"],
-    "bug_numbers": [1687358],
-    "expires_in_version": "never",
-    "kind": "exponential",
-    "high": 2000,
-    "n_buckets": 100,
-    "releaseChannelCollection": "opt-out",
-    "description": "Number of lazy-loaded images that were started to load but didn't reach to the viewport eventually"
-  },
-  "LAZYLOAD_IMAGE_VIEWPORT_LOADING": {
-    "record_in_processes": ["main", "content"],
-    "products": ["firefox"],
-    "alert_emails": ["sefeng@mozilla.com"],
-    "bug_numbers": [1687358],
-    "expires_in_version": "never",
-    "kind": "exponential",
-    "high": 2000,
-    "n_buckets": 100,
-    "releaseChannelCollection": "opt-out",
-    "description": "Number of lazy-loaded images that reached the viewport which were not done loading when they did so."
-  },
-  "LAZYLOAD_IMAGE_VIEWPORT_LOADED": {
-    "record_in_processes": ["main", "content"],
-    "products": ["firefox"],
-    "alert_emails": ["sefeng@mozilla.com"],
-    "bug_numbers": [1687358],
-    "expires_in_version": "never",
-    "kind": "exponential",
-    "high": 2000,
-    "n_buckets": 100,
-    "releaseChannelCollection": "opt-out",
-    "description": "Number of lazy-loaded images that reached the viewport and were done loading when they did so."
-  },
   "LOADED_TAB_COUNT": {
     "record_in_processes": ["main"],
     "products": ["firefox"],
@@ -8192,18 +8132,6 @@
     "alert_emails": ["tdsmith@mozilla.com", "perf-telemetry-alerts@mozilla.com", "product-metrics-telemetry-alerts@mozilla.com"],
     "releaseChannelCollection": "opt-out"
   },
-  "FX_LAZYLOAD_IMAGE_PAGE_LOAD_MS": {
-    "record_in_processes": ["main"],
-    "products": ["firefox"],
-    "expires_in_version": "never",
-    "kind": "linear",
-    "high": 10000,
-    "n_buckets": 100,
-    "description": "Firefox: Time taken to load a page that has at least one `loading='lazy'` image. (This metric includes both loads and reloads)",
-    "bug_numbers": [1692350],
-    "alert_emails": ["sefeng@mozilla.com", "perf-telemetry-alerts@mozilla.com"],
-    "releaseChannelCollection": "opt-out"
-  },
   "FX_PAGE_RELOAD_NORMAL_MS": {
     "record_in_processes": ["main"],
     "products": ["firefox", "fennec"],