[CompositeAfterPaint] Prefer composited scrolling of composited iframe

If an iframe has direct compositing reason, then prefer composited
scrolling for the content LayoutView.

Change-Id: Id257a5253ad792a4fc2acec8860940a612bc43f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2107612Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#752311}

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

@@ -10,6 +10,7 @@
 #include "third_party/blink/renderer/core/frame/local_frame_view.h"
 #include "third_party/blink/renderer/core/frame/settings.h"
 #include "third_party/blink/renderer/core/fullscreen/fullscreen.h"
+#include "third_party/blink/renderer/core/layout/layout_embedded_content.h"
 #include "third_party/blink/renderer/core/layout/layout_video.h"
 #include "third_party/blink/renderer/core/layout/layout_view.h"
 #include "third_party/blink/renderer/core/page/page.h"
@@ -138,6 +139,15 @@ CompositingReasons CompositingReasonFinder::DirectReasonsForPaintProperties(
     if (RuntimeEnabledFeatures::CompositeAfterPaintEnabled()) {
       bool force_prefer_compositing_to_lcd_text =
           reasons != CompositingReason::kNone;
+
+      if (!force_prefer_compositing_to_lcd_text && object.IsLayoutView()) {
+        if (auto* owner_object = object.GetFrame()->OwnerLayoutObject()) {
+          force_prefer_compositing_to_lcd_text =
+              DirectReasonsForPaintProperties(*owner_object) !=
+              CompositingReason::kNone;
+        }
+      }
+
       if (scrollable_area->ComputeNeedsCompositedScrolling(
               force_prefer_compositing_to_lcd_text)) {
         reasons |= CompositingReason::kOverflowScrolling;

third_party/blink/renderer/platform/graphics/compositing/paint_artifact_compositor.cc

@@ -384,7 +384,8 @@ void PaintArtifactCompositor::UpdateNonFastScrollableRegions(
     cc::Layer* layer,
     const gfx::Vector2dF& layer_offset,
     const PropertyTreeState& layer_state,
-    const PaintChunkSubset& paint_chunks) {
+    const PaintChunkSubset& paint_chunks,
+    PropertyTreeManager* property_tree_manager) {
   cc::Region non_fast_scrollable_regions_in_layer_space;
   for (const auto& chunk : paint_chunks) {
     // Add any non-fast scrollable hit test data from the paint chunk.
@@ -402,6 +403,12 @@ void PaintArtifactCompositor::UpdateNonFastScrollableRegions(
         auto scroll_element_id = scroll_node.GetCompositorElementId();
         if (layer->element_id() == scroll_element_id)
           continue;
+        // Ensure the cc scroll node to prepare for possible descendant nodes
+        // referenced by later composited layers. This can't be done by ensuring
+        // parent transform node in EnsureCompositorTransformNode() if the
+        // transform tree and the scroll tree have different topologies.
+        DCHECK(property_tree_manager);
+        property_tree_manager->EnsureCompositorScrollNode(*scroll_translation);
       }
     }
 
@@ -1245,9 +1252,9 @@ void PaintArtifactCompositor::Update(
           pending_layer.paint_chunk_indices);
       UpdateTouchActionRects(layer.get(), layer->offset_to_transform_parent(),
                              property_state, paint_chunks);
-      UpdateNonFastScrollableRegions(layer.get(),
-                                     layer->offset_to_transform_parent(),
-                                     property_state, paint_chunks);
+      UpdateNonFastScrollableRegions(
+          layer.get(), layer->offset_to_transform_parent(), property_state,
+          paint_chunks, &property_tree_manager);
     }
 
     layer->SetLayerTreeHost(root_layer_->layer_tree_host());

third_party/blink/renderer/platform/graphics/compositing/paint_artifact_compositor.h

@@ -40,6 +40,7 @@ namespace blink {
 class ContentLayerClientImpl;
 class JSONObject;
 class PaintArtifact;
+class PropertyTreeManager;
 class SynthesizedClip;
 struct PaintChunk;
 
@@ -196,7 +197,8 @@ class PLATFORM_EXPORT PaintArtifactCompositor final
       cc::Layer*,
       const gfx::Vector2dF& layer_offset,
       const PropertyTreeState& layer_state,
-      const PaintChunkSubset& paint_chunks);
+      const PaintChunkSubset& paint_chunks,
+      PropertyTreeManager* = nullptr);
 
   void SetNeedsUpdate() { needs_update_ = true; }
   bool NeedsUpdate() const { return needs_update_; }

third_party/blink/web_tests/FlagExpectations/composite-after-paint

@@ -132,10 +132,6 @@ http/tests/devtools/layers/layer-compositing-reasons.js [ Failure ]
 # Missing WheelEventHandler
 http/tests/devtools/layers/layer-scroll-rects-get.js [ Failure ]
 
-# CAP doesn't force compositing of iframe containing composited content.
-compositing/rtl/rtl-iframe-absolute-overflow-scrolled.html [ Failure ]
-compositing/rtl/rtl-iframe-fixed-overflow-scrolled.html [ Failure ]
-
 # Wrong contentsOpaque of the scrollbar layer with transparent track.
 fast/frames/transparent-scrollbar.html [ Failure ]
 

third_party/blink/web_tests/compositing/rtl/rtl-iframe-absolute-overflow-scrolled.html

@@ -7,6 +7,7 @@
 
     iframe {
         position: absolute;
+        will-change: transform;
         top: 0px;
         left: 0px;
         width: 400px;

third_party/blink/web_tests/compositing/rtl/rtl-iframe-fixed-overflow-scrolled.html

@@ -7,6 +7,7 @@
 
     iframe {
         position: absolute;
+        will-change: transform;
         top: 0px;
         left: 0px;
         width: 400px;

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/iframes/composited-parent-iframe-expected.txt

@@ -12,6 +12,19 @@
       "bounds": [390, 240],
       "transform": 1
     },
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "bounds": [285, 230],
+      "contentsOpaque": true,
+      "backgroundColor": "#C0C0C0",
+      "transform": 2
+    },
+    {
+      "name": "VerticalScrollbar",
+      "position": [285, 0],
+      "bounds": [15, 150],
+      "transform": 2
+    },
     {
       "name": "LayoutNGBlockFlow DIV id='iframe-content' class='box'",
       "bounds": [210, 210],

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/iframes/connect-compositing-iframe-expected.txt

@@ -12,6 +12,19 @@
       "bounds": [390, 240],
       "transform": 1
     },
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "bounds": [285, 230],
+      "contentsOpaque": true,
+      "backgroundColor": "#C0C0C0",
+      "transform": 2
+    },
+    {
+      "name": "VerticalScrollbar",
+      "position": [285, 0],
+      "bounds": [15, 150],
+      "transform": 2
+    },
     {
       "name": "LayoutNGBlockFlow DIV id='test' class='composited box'",
       "bounds": [210, 210],

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/iframes/connect-compositing-iframe2-expected.txt

@@ -12,6 +12,19 @@
       "bounds": [390, 240],
       "transform": 1
     },
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "bounds": [285, 230],
+      "contentsOpaque": true,
+      "backgroundColor": "#C0C0C0",
+      "transform": 2
+    },
+    {
+      "name": "VerticalScrollbar",
+      "position": [285, 0],
+      "bounds": [15, 150],
+      "transform": 2
+    },
     {
       "name": "LayoutNGBlockFlow DIV id='iframe-content' class='box'",
       "bounds": [210, 210],

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/iframes/connect-compositing-iframe3-expected.txt

@@ -12,6 +12,19 @@
       "bounds": [390, 240],
       "transform": 1
     },
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "bounds": [285, 230],
+      "contentsOpaque": true,
+      "backgroundColor": "#C0C0C0",
+      "transform": 2
+    },
+    {
+      "name": "VerticalScrollbar",
+      "position": [285, 0],
+      "bounds": [15, 150],
+      "transform": 2
+    },
     {
       "name": "LayoutNGBlockFlow DIV id='iframe-content' class='box'",
       "bounds": [210, 210],

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/iframes/resizer-expected.txt

@@ -12,12 +12,31 @@
       "backgroundColor": "#9A9A9A",
       "transform": 1
     },
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "bounds": [285, 230],
+      "contentsOpaque": true,
+      "backgroundColor": "#C0C0C0",
+      "transform": 2
+    },
+    {
+      "name": "VerticalScrollbar",
+      "position": [285, 0],
+      "bounds": [15, 150],
+      "transform": 2
+    },
     {
       "name": "LayoutNGBlockFlow DIV id='iframe-content' class='box'",
       "bounds": [210, 210],
       "contentsOpaque": true,
       "backgroundColor": "#0000FF",
       "transform": 3
+    },
+    {
+      "name": "Scroll corner of LayoutIFrame IFRAME class='container'",
+      "position": [287, 137],
+      "bounds": [15, 15],
+      "transform": 1
     }
   ],
   "transforms": [

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/rtl/rtl-iframe-absolute-overflow-scrolled-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "position": [15, 0],
+      "bounds": [1000, 1000],
+      "contentsOpaque": true,
+      "backgroundColor": "#FF0000",
+      "transform": 1
+    },
+    {
+      "name": "HorizontalScrollbar",
+      "position": [15, 385],
+      "bounds": [385, 15]
+    },
+    {
+      "name": "VerticalScrollbar",
+      "bounds": [15, 385]
+    },
+    {
+      "name": "Scroll corner of LayoutView #document",
+      "position": [0, 385],
+      "bounds": [15, 15]
+    },
+    {
+      "name": "LayoutNGBlockFlow (positioned) DIV id='layer' class='positioned'",
+      "bounds": [100, 100],
+      "contentsOpaque": true,
+      "backgroundColor": "#008000",
+      "transform": 2
+    }
+  ],
+  "transforms": [
+    {
+      "id": 1,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [-615, 0, 0, 1]
+      ]
+    },
+    {
+      "id": 2,
+      "parent": 1,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [66, 50, 0, 1]
+      ]
+    }
+  ]
+}
+

third_party/blink/web_tests/flag-specific/composite-after-paint/compositing/rtl/rtl-iframe-fixed-overflow-scrolled-expected.txt

+{
+  "layers": [
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "backgroundColor": "#FFFFFF"
+    },
+    {
+      "name": "Scrolling background of LayoutView #document",
+      "position": [15, 0],
+      "bounds": [1000, 1000],
+      "contentsOpaque": true,
+      "backgroundColor": "#FF0000",
+      "transform": 1
+    },
+    {
+      "name": "HorizontalScrollbar",
+      "position": [15, 385],
+      "bounds": [385, 15]
+    },
+    {
+      "name": "VerticalScrollbar",
+      "bounds": [15, 385]
+    },
+    {
+      "name": "Scroll corner of LayoutView #document",
+      "position": [0, 385],
+      "bounds": [15, 15]
+    },
+    {
+      "name": "LayoutNGBlockFlow (positioned) DIV class='positioned indicator'",
+      "bounds": [100, 100],
+      "contentsOpaque": true,
+      "backgroundColor": "#FF0000",
+      "transform": 2
+    },
+    {
+      "name": "LayoutNGBlockFlow (positioned) DIV class='positioned layer'",
+      "bounds": [100, 100],
+      "contentsOpaque": true,
+      "backgroundColor": "#008000",
+      "transform": 3
+    }
+  ],
+  "transforms": [
+    {
+      "id": 1,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [-615, 0, 0, 1]
+      ]
+    },
+    {
+      "id": 2,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [65, 50, 0, 1]
+      ]
+    },
+    {
+      "id": 3,
+      "transform": [
+        [1, 0, 0, 0],
+        [0, 1, 0, 0],
+        [0, 0, 1, 0],
+        [65, 50, 0, 1]
+      ]
+    }
+  ]
+}
+