content-visibility: Early out in PaintLayerCompositor if locked.

This patch ensures that we don't try and update assignments if
the layout view is locked in its parent frame.

If the view is locked, it means that we skipped processing prepaint
for it, which means that the contents here might not have the
LocalBorderBoxProperties (created during prepaint). However, the
assignment needs the properties to do its work.

Since the frame walk here is unconditional, there is no need to
keep track of the dirty bit flags, as long as we don't clear the
flags on the compositor itself. This is similar to how the throttling
logic behaves.

R=chrishtr@chromium.org

Bug: 1128790
Change-Id: Ic325b618161c68d5886d0a5c0926cbd29e81d38e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2422265
Commit-Queue: vmpstr <vmpstr@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809314}

third_party/blink/renderer/core/display_lock/display_lock_utilities.cc

@@ -597,4 +597,18 @@ bool DisplayLockUtilities::UpdateStyleAndLayoutForRangeIfNeeded(
   return !forced_context_list_.IsEmpty();
 }
 
+bool DisplayLockUtilities::PrePaintBlockedInParentFrame(LayoutView* view) {
+  auto* owner = view->GetFrameView()->GetFrame().OwnerLayoutObject();
+  if (!owner)
+    return false;
+
+  auto* element = NearestLockedInclusiveAncestor(*owner);
+  while (element) {
+    if (!element->GetDisplayLockContext()->ShouldPrePaintChildren())
+      return true;
+    element = NearestLockedExclusiveAncestor(*element);
+  }
+  return false;
+}
+
 }  // namespace blink

third_party/blink/renderer/core/display_lock/display_lock_utilities.h

@@ -172,6 +172,8 @@ class CORE_EXPORT DisplayLockUtilities {
                                const EphemeralRangeInFlatTree& new_selection);
   static void SelectionRemovedFromDocument(Document& document);
 
+  static bool PrePaintBlockedInParentFrame(LayoutView* layout_view);
+
  private:
   static bool UpdateStyleAndLayoutForRangeIfNeeded(
       const EphemeralRangeInFlatTree& range,

third_party/blink/renderer/core/layout/layout_tree_as_text.cc

@@ -571,16 +571,17 @@ void Write(WTF::TextStream& ts,
         continue;
       Write(ts, *child, indent + 1, behavior);
     }
-  }
 
-  if (o.IsLayoutEmbeddedContent()) {
-    FrameView* frame_view = ToLayoutEmbeddedContent(o).ChildFrameView();
-    if (auto* local_frame_view = DynamicTo<LocalFrameView>(frame_view)) {
-      if (auto* layout_view = local_frame_view->GetLayoutView()) {
-        layout_view->GetDocument().UpdateStyleAndLayout(
-            DocumentUpdateReason::kTest);
-        if (auto* layer = layout_view->Layer()) {
-          LayoutTreeAsText::WriteLayers(ts, layer, layer, indent + 1, behavior);
+    if (o.IsLayoutEmbeddedContent()) {
+      FrameView* frame_view = ToLayoutEmbeddedContent(o).ChildFrameView();
+      if (auto* local_frame_view = DynamicTo<LocalFrameView>(frame_view)) {
+        if (auto* layout_view = local_frame_view->GetLayoutView()) {
+          layout_view->GetDocument().UpdateStyleAndLayout(
+              DocumentUpdateReason::kTest);
+          if (auto* layer = layout_view->Layer()) {
+            LayoutTreeAsText::WriteLayers(ts, layer, layer, indent + 1,
+                                          behavior);
+          }
         }
       }
     }
@@ -739,6 +740,9 @@ void LayoutTreeAsText::WriteLayers(WTF::TextStream& ts,
   }
 #endif
 
+  bool should_paint_children =
+      !layer->GetLayoutObject().ChildLayoutBlockedByDisplayLock();
+
   const auto& neg_list = ChildLayers(layer, kNegativeZOrderChildren);
   bool paints_background_separately = !neg_list.IsEmpty();
   if (should_paint && paints_background_separately) {
@@ -747,7 +751,7 @@ void LayoutTreeAsText::WriteLayers(WTF::TextStream& ts,
           behavior, marked_layer);
   }
 
-  if (!neg_list.IsEmpty()) {
+  if (should_paint_children && !neg_list.IsEmpty()) {
     int curr_indent = indent;
     if (behavior & kLayoutAsTextShowLayerNesting) {
       WriteIndent(ts, indent);
@@ -767,7 +771,7 @@ void LayoutTreeAsText::WriteLayers(WTF::TextStream& ts,
   }
 
   const auto& normal_flow_list = ChildLayers(layer, kNormalFlowChildren);
-  if (!normal_flow_list.IsEmpty()) {
+  if (should_paint_children && !normal_flow_list.IsEmpty()) {
     int curr_indent = indent;
     if (behavior & kLayoutAsTextShowLayerNesting) {
       WriteIndent(ts, indent);
@@ -779,7 +783,7 @@ void LayoutTreeAsText::WriteLayers(WTF::TextStream& ts,
   }
 
   const auto& pos_list = ChildLayers(layer, kPositiveZOrderChildren);
-  if (!pos_list.IsEmpty()) {
+  if (should_paint_children && !pos_list.IsEmpty()) {
     int curr_indent = indent;
     if (behavior & kLayoutAsTextShowLayerNesting) {
       WriteIndent(ts, indent);

third_party/blink/renderer/core/paint/compositing/paint_layer_compositor.cc

@@ -30,6 +30,7 @@
 #include "third_party/blink/renderer/core/animation/document_animations.h"
 #include "third_party/blink/renderer/core/animation/document_timeline.h"
 #include "third_party/blink/renderer/core/animation/element_animations.h"
+#include "third_party/blink/renderer/core/display_lock/display_lock_utilities.h"
 #include "third_party/blink/renderer/core/dom/dom_node_ids.h"
 #include "third_party/blink/renderer/core/editing/frame_selection.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
@@ -207,6 +208,9 @@ void PaintLayerCompositor::UpdateAssignmentsIfNeededRecursiveInternal(
   if (layout_view_->GetFrameView()->ShouldThrottleRendering())
     return;
 
+  if (DisplayLockUtilities::PrePaintBlockedInParentFrame(layout_view_))
+    return;
+
   Lifecycle().AdvanceTo(DocumentLifecycle::kInCompositingAssignmentsUpdate);
 
   LocalFrameView* view = layout_view_->GetFrameView();
@@ -245,7 +249,8 @@ void PaintLayerCompositor::UpdateAssignmentsIfNeededRecursiveInternal(
 #if DCHECK_IS_ON()
   DCHECK_EQ(Lifecycle().GetState(),
             DocumentLifecycle::kCompositingAssignmentsClean);
-  AssertNoUnresolvedDirtyBits();
+  if (!DisplayLockUtilities::PrePaintBlockedInParentFrame(layout_view_))
+    AssertNoUnresolvedDirtyBits();
   for (Frame* child =
            layout_view_->GetFrameView()->GetFrame().Tree().FirstChild();
        child; child = child->Tree().NextSibling()) {
@@ -253,7 +258,9 @@ void PaintLayerCompositor::UpdateAssignmentsIfNeededRecursiveInternal(
     if (!local_frame)
       continue;
     if (local_frame->ShouldThrottleRendering() ||
-        !local_frame->ContentLayoutObject())
+        !local_frame->ContentLayoutObject() ||
+        DisplayLockUtilities::PrePaintBlockedInParentFrame(
+            local_frame->ContentLayoutObject()))
       continue;
     local_frame->ContentLayoutObject()
         ->Compositor()

third_party/blink/web_tests/compositing/iframes/content-visibility-hidden-div-with-frame-expected.txt

+layer at (0,0) size 800x600
+  LayoutView at (0,0) size 800x600
+layer at (0,0) size 800x200
+  LayoutNGBlockFlow {HTML} at (0,0) size 800x200
+    LayoutNGBlockFlow {BODY} at (0,0) size 800x200
+layer at (0,0) size 800x0
+  LayoutNGBlockFlow {DIV} at (0,0) size 800x0 (display-locked)

third_party/blink/web_tests/compositing/iframes/content-visibility-hidden-div-with-frame.html

+<!DOCTYPE html>
+
+<style>
+iframe {
+  width: 10px;
+  height: 10px;
+  border: none;
+  padding: 0;
+  margin: 0;
+}
+body {
+  padding: 0;
+  margin: 0;
+  height: 200px;
+}
+</style>
+<div id=d>
+<iframe id=frame></iframe>
+</div>
+
+<script>
+if (window.testRunner)
+  testRunner.waitUntilDone();
+
+requestAnimationFrame(() => requestAnimationFrame(() => {
+  d.style = "content-visibility: hidden";
+  frame.srcdoc = '<table> <marquee></marquee></table>';
+  if (window.testRunner) {
+      testRunner.dumpAsLayout();
+      testRunner.notifyDone();
+  }
+}));
+</script>
+

third_party/blink/web_tests/compositing/iframes/content-visibility-hidden-frame-expected.txt

+layer at (0,0) size 800x600
+  LayoutView at (0,0) size 800x600
+layer at (0,0) size 800x200
+  LayoutNGBlockFlow {HTML} at (0,0) size 800x200
+    LayoutNGBlockFlow {BODY} at (0,0) size 800x200
+layer at (8,7) size 10x10
+  LayoutIFrame (positioned) {IFRAME} at (8,7) size 10x10 (display-locked)

third_party/blink/web_tests/compositing/iframes/content-visibility-hidden-frame.html

+<!DOCTYPE html>
+
+<style>
+iframe {
+  width: 10px;
+  height: 10px;
+  border: none;
+  padding: 0;
+  margin: 0;
+  position: absolute;
+  top: 7px;
+  left: 8px;
+}
+body {
+  padding: 0;
+  margin: 0;
+  height: 200px;
+}
+</style>
+<iframe id=frame style="content-visibility: hidden" srcdoc='<table> <marquee></marquee></table>'></iframe>
+
+<script>
+if (window.testRunner)
+  testRunner.dumpAsLayout();
+</script>
+

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/iframes/content-visibility-hidden-div-with-frame-expected.txt

+layer at (0,0) size 800x600
+  LayoutView at (0,0) size 800x600
+layer at (0,0) size 800x200
+  LayoutBlockFlow {HTML} at (0,0) size 800x200
+    LayoutBlockFlow {BODY} at (0,0) size 800x200
+layer at (0,0) size 800x0
+  LayoutBlockFlow {DIV} at (0,0) size 800x0 (display-locked)

third_party/blink/web_tests/flag-specific/disable-layout-ng/compositing/iframes/content-visibility-hidden-frame-expected.txt

+layer at (0,0) size 800x600
+  LayoutView at (0,0) size 800x600
+layer at (0,0) size 800x200
+  LayoutBlockFlow {HTML} at (0,0) size 800x200
+    LayoutBlockFlow {BODY} at (0,0) size 800x200
+layer at (8,7) size 10x10
+  LayoutIFrame (positioned) {IFRAME} at (8,7) size 10x10 (display-locked)