Revert "Deferred Shaping: Add a counter for tall IFCs" and "Deferred …

…Shaping: Speculative fix for memory regressions"

This CL reverts crrev.com/931342 and crrev.com/931591.
It seems they consumed additional 400-700KB memory on each of pages.

Bug: 1259085, 1259877, 1259884, 1259873, 1259919, 1260075
Change-Id: Idae4dfd7e0c87a6ac996ec4c2a943adecab173f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3224759
Commit-Queue: Koji Ishii <kojii@chromium.org>
Auto-Submit: Kent Tamura <tkent@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/main@{#931863}

third_party/blink/public/mojom/web_feature/web_feature.mojom

@@ -3367,7 +3367,6 @@ enum WebFeature {
   kFlexboxAlignSingleLineDifference = 4057,
   kExternalProtocolBlockedBySandbox = 4058,
   kWebAssemblyDynamicTiering = 4059,
-  kDeferredShapingTallerIfc = 4060,
   kReadOrWriteWebDatabase = 4061,
 
   // Add new features immediately above this line. Don't change assigned

third_party/blink/renderer/core/dom/document.cc

@@ -78,7 +78,6 @@
 #include "third_party/blink/renderer/bindings/core/v8/source_location.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_element_creation_options.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_element_registration_options.h"
-#include "third_party/blink/renderer/bindings/core/v8/v8_idle_request_options.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_interest_cohort.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_throw_dom_exception.h"
 #include "third_party/blink/renderer/bindings/core/v8/v8_union_elementcreationoptions_string.h"
@@ -416,97 +415,6 @@ bool DefaultFaviconAllowedByCSP(const Document* document, const IconURL& icon) {
       ContentSecurityPolicy::CheckHeaderType::kCheckAll);
 }
 
-class IdleWebFeatureTask : public IdleTask {
- public:
-  explicit IdleWebFeatureTask(Document& document)
-      : IdleTask(), document_(document) {}
-
-  void Trace(Visitor* visitor) const override {
-    visitor->Trace(document_);
-    IdleTask::Trace(visitor);
-  }
-
-  const char* NameInHeapSnapshot() const override {
-    return "WebPlatformFeatureStatisticsTask";
-  }
-
-  void invoke(IdleDeadline*) override {
-    Document* document = document_.Get();
-    if (!document || !document->View())
-      return;
-    if (layout_count_ != document->View()->LayoutCount()) {
-      layout_count_ = document->View()->LayoutCount();
-      if (!document->GetLayoutView())
-        return;
-      const LayoutView& view = *document->GetLayoutView();
-      PhysicalSize viewport_size(LayoutUnit(view.ViewWidth()),
-                                 LayoutUnit(view.ViewHeight()));
-      if (FindTallerIfc(view, viewport_size)) {
-        UseCounter::Count(*document, WebFeature::kDeferredShapingTallerIfc);
-        return;
-      }
-      if (first_traverse_time_.is_null())
-        first_traverse_time_ = base::Time::Now();
-    }
-    // Stop counting after kCountDuration from the first traverse.
-    constexpr base::TimeDelta kCountDuration = base::Seconds(30);
-    if (first_traverse_time_.is_null() ||
-        base::Time::Now() < first_traverse_time_ + kCountDuration)
-      document->RequestIdleCallback(this, IdleRequestOptions::Create());
-  }
-
- private:
-  static bool FindTallerIfc(const LayoutBox& parent,
-                            const PhysicalSize& viewport_size) {
-    for (const auto* child = parent.SlowFirstChild(); child;
-         child = child->NextSibling()) {
-      const auto* box = DynamicTo<LayoutBox>(child);
-      if (!box)
-        continue;
-      PhysicalSize new_size = viewport_size;
-      if (box->HasNonVisibleOverflow())
-        new_size = {box->Size().Width(), box->Size().Height()};
-      if (box->IsLayoutBlockFlow() && box->ChildrenInline() &&
-          !box->IsPositioned()) {
-        if (IsTallerBox(*box, new_size) && HasInlineOrNonWhitespaceText(*box))
-          return true;
-      }
-      if (FindTallerIfc(*box, new_size))
-        return true;
-    }
-    return false;
-  }
-
-  static bool IsTallerBox(const LayoutBox& box,
-                          const PhysicalSize& viewport_size) {
-    // This function returns false for viewport block size == 0 because
-    // the counter is for "partial" deferred shaping.
-    if (box.IsHorizontalWritingMode()) {
-      return viewport_size.height > LayoutUnit() &&
-             box.Size().Height() > viewport_size.height;
-    }
-    return viewport_size.width > LayoutUnit() &&
-           box.Size().Width() > viewport_size.width;
-  }
-
-  static bool HasInlineOrNonWhitespaceText(const LayoutBox& ifc) {
-    for (const auto* child = ifc.SlowFirstChild(); child;
-         child = child->NextSibling()) {
-      if (child->IsLayoutInline())
-        return true;
-      if (const auto* text = DynamicTo<LayoutText>(child)) {
-        if (!text->ContainsOnlyWhitespace(0, text->TextLength()))
-          return true;
-      }
-    }
-    return false;
-  }
-
-  WeakMember<Document> document_;
-  base::Time first_traverse_time_;
-  uint32_t layout_count_ = 0;
-};
-
 }  // namespace
 
 static const unsigned kCMaxWriteRecursionDepth = 21;
@@ -2768,14 +2676,6 @@ void Document::Initialize() {
 
   if (View())
     View()->DidAttachDocument();
-
-  // We need to check IsRunningWebTest() and null Url(). Some tests fail
-  // without the check because of a scheduler behavior difference.
-  if (GetFrame()->IsLocalRoot() && !WebTestSupport::IsRunningWebTest() &&
-      !Url().IsNull()) {
-    RequestIdleCallback(MakeGarbageCollected<IdleWebFeatureTask>(*this),
-                        IdleRequestOptions::Create());
-  }
 }
 
 void Document::Shutdown() {

third_party/blink/renderer/core/frame/local_frame_view.cc

@@ -249,7 +249,7 @@ LocalFrameView::LocalFrameView(LocalFrame& frame, IntRect frame_rect)
       can_have_scrollbars_(true),
       has_pending_layout_(false),
       layout_scheduling_enabled_(true),
-      layout_count_(0),
+      layout_count_for_testing_(0),
       lifecycle_update_count_for_testing_(0),
       // We want plugin updates to happen in FIFO order with loading tasks.
       update_plugins_timer_(frame.GetTaskRunner(TaskType::kInternalLoading),
@@ -1907,7 +1907,7 @@ void LocalFrameView::PerformPostLayoutTasks(bool visual_viewport_size_changed) {
   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("blink.debug.layout.trees"), "LayoutTree", this,
       TracedLayoutObject::Create(*GetLayoutView(), true));
-  layout_count_++;
+  layout_count_for_testing_++;
   Document* document = GetFrame().GetDocument();
   DCHECK(document);
   if (AXObjectCache* cache = document->ExistingAXObjectCache()) {

third_party/blink/renderer/core/frame/local_frame_view.h

@@ -189,10 +189,7 @@ class CORE_EXPORT LocalFrameView final
   // Returns true if commits will be deferred for first contentful paint.
   bool WillDoPaintHoldingForFCP() const;
 
-  // TODO(crbug.com/1259085): Remove LayoutCount() and rename layout_count_
-  // to layout_count_for_testing_ when we remove IdleWebFeatureTask.
-  unsigned LayoutCount() const { return layout_count_; }
-  unsigned LayoutCountForTesting() const { return layout_count_; }
+  unsigned LayoutCountForTesting() const { return layout_count_for_testing_; }
   unsigned LifecycleUpdateCountForTesting() const {
     return lifecycle_update_count_for_testing_;
   }
@@ -1022,7 +1019,7 @@ class CORE_EXPORT LocalFrameView final
   DepthOrderedLayoutObjectList orthogonal_writing_mode_root_list_;
 
   bool layout_scheduling_enabled_;
-  unsigned layout_count_;
+  unsigned layout_count_for_testing_;
   unsigned lifecycle_update_count_for_testing_;
   HeapTaskRunnerTimer<LocalFrameView> update_plugins_timer_;
 

tools/metrics/histograms/enums.xml

@@ -34932,7 +34932,7 @@ Called by update_use_counter_feature_enum.py.-->
   <int value="4057" label="FlexboxAlignSingleLineDifference"/>
   <int value="4058" label="ExternalProtocolBlockedBySandbox"/>
   <int value="4059" label="WebAssemblyDynamicTiering"/>
-  <int value="4060" label="DeferredShapingTallerIfc"/>
+  <int value="4060" label="OBSOLETE_DeferredShapingTallerIfc"/>
   <int value="4061" label="ReadOrWriteWebDatabase"/>
 </enum>