[BGPT] Fix paint/pagination/composited-paginated-outlined-box.html

For SPv1, we don't fragment a composited or squashed layer, but should
create a single fragment for it under the parent fragment where the
layer's border box starts. Previously we used overflow box to determine
fragments causing the composited/squashed layer to be placed in wrong
parent fragment when the layer has overflows. Now use border box rect
in the case.

Bug: 854192
Cq-Include-Trybots: luci.chromium.try:linux-blink-gen-property-trees;luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ib05e8629f423b3a1960de1fc8f3989c42f54766f
Reviewed-on: https://chromium-review.googlesource.com/1180377Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584615}

third_party/WebKit/LayoutTests/FlagExpectations/enable-blink-gen-property-trees

@@ -256,7 +256,6 @@ crbug.com/853945 fast/block/positioning/rtl-fixed-positioning.html [ Failure ]
 # Composited multicolumn paints differently.
 crbug.com/854192 fast/multicol/composited-layer-nested.html [ Failure ]
 crbug.com/854192 fast/multicol/vertical-rl/composited-relpos-overlapping-will-change.html [ Failure ]
-crbug.com/854192 paint/pagination/composited-paginated-outlined-box.html [ Failure ]
 
 Bug(none) fast/dom/scroll-reveal-left-overflow.html [ Failure ]
 Bug(none) fast/dom/scroll-reveal-top-overflow.html [ Failure ]

third_party/blink/renderer/core/paint/paint_property_tree_builder.cc

@@ -1553,13 +1553,27 @@ static bool IsRepeatingTableSection(const LayoutObject& object) {
 static LayoutRect BoundingBoxInPaginationContainer(
     const LayoutObject& object,
     const PaintLayer& enclosing_pagination_layer) {
-  // Non-boxes that have no layer paint in the space of their containing block.
-  if (!object.IsBox() && !object.HasLayer()) {
+  // The special path for fragmented layers ensures that the bounding box also
+  // covers contents visual overflow, so that the fragments will cover all
+  // fragments of contents except for self-painting layers, because we initiate
+  // fragment painting of contents from the layer.
+  if (object.HasLayer() &&
+      ToLayoutBoxModelObject(object)
+          .Layer()
+          ->ShouldFragmentCompositedBounds() &&
+      // Table section may repeat, and doesn't need the special layer path
+      // because it doesn't have contents visual overflow.
+      !object.IsTableSection()) {
+    return ToLayoutBoxModelObject(object).Layer()->PhysicalBoundingBox(
+        &enclosing_pagination_layer);
+  }
+
+  // Non-boxes paint in the space of their containing block.
+  if (!object.IsBox()) {
     const LayoutBox& containining_block = *object.ContainingBlock();
     LayoutRect bounds_rect;
-    // For non-SVG we can get a more accurate result
-    // with LocalVisualRect, instead of falling back to the bounds of the
-    // enclosing block.
+    // For non-SVG we can get a more accurate result with LocalVisualRect,
+    // instead of falling back to the bounds of the enclosing block.
     if (!object.IsSVG()) {
       bounds_rect = object.LocalVisualRect();
       containining_block.FlipForWritingMode(bounds_rect);
@@ -1571,17 +1585,6 @@ static LayoutRect BoundingBoxInPaginationContainer(
                                        enclosing_pagination_layer);
   }
 
-  // The special path for layers ensures that the bounding box also covers
-  // contents visual overflow, so that the fragments will cover all fragments of
-  // contents except for self-painting layers, because we initiate fragment
-  // painting of contents from the layer.
-  // Table section may repeat, and doesn't need the special layer path because
-  // it doesn't have contents visual overflow.
-  if (object.HasLayer() && !object.IsTableSection()) {
-    return ToLayoutBoxModelObject(object).Layer()->PhysicalBoundingBox(
-        &enclosing_pagination_layer);
-  }
-
   // Compute the bounding box without transforms.
   // The object is guaranteed to be a box due to the logic above.
   const LayoutBox& box = ToLayoutBox(object);
@@ -1991,6 +1994,7 @@ void PaintPropertyTreeBuilder::UpdateCompositedLayerPaginationOffset() {
   // under the pagination layer. SPv1* doesn't fragment composited layers,
   // but we still need to set correct pagination offset for correct paint
   // offset calculation.
+  DCHECK(!context_.painting_layer->ShouldFragmentCompositedBounds());
   FragmentData& first_fragment =
       object_.GetMutableForPainting().FirstFragment();
   bool is_paint_invalidation_container = object_.IsPaintInvalidationContainer();