Implement PaintLayer::scrollsWithViewport for SPv2.

third_party/WebKit/Source/core/paint/PaintLayerTest.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayerTest.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerTest.cpp b/third_party/WebKit/Source/core/paint/PaintLayerTest.cpp
index 4e967a7c2a78746a4a97cc0c770f556b83ab0282..4896c132adc52e6317c47b69063d704aa2d44236 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerTest.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerTest.cpp
@@ -7,12 +7,36 @@
 #include "core/layout/LayoutBoxModelObject.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutView.h"
+#include "platform/testing/RuntimeEnabledFeaturesTestHelpers.h"
 
 namespace blink {
 
-using PaintLayerTest = RenderingTest;
+typedef std::pair<bool, bool> SlimmingPaintAndRootLayerScrolling;
+class PaintLayerTest
+    : public ::testing::WithParamInterface<SlimmingPaintAndRootLayerScrolling>,
+      private ScopedSlimmingPaintV2ForTest,
+      private ScopedRootLayerScrollingForTest,
+      public RenderingTest {
+ public:
+  PaintLayerTest()
+      : ScopedSlimmingPaintV2ForTest(GetParam().first),
+        ScopedRootLayerScrollingForTest(GetParam().second),
+        RenderingTest(SingleChildFrameLoaderClient::create()) {}
+};
+
+SlimmingPaintAndRootLayerScrolling foo[] = {
+    SlimmingPaintAndRootLayerScrolling(false, false),
+    SlimmingPaintAndRootLayerScrolling(true, false),
+    SlimmingPaintAndRootLayerScrolling(false, true),
+    SlimmingPaintAndRootLayerScrolling(true, true)};
+
+INSTANTIATE_TEST_CASE_P(All, PaintLayerTest, ::testing::ValuesIn(foo));
+
+TEST_P(PaintLayerTest, CompositedBoundsAbsPosGrandchild) {
+  // TODO(chrishtr): fix this test for SPv2
+  if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+    return;
 
-TEST_F(PaintLayerTest, CompositedBoundsAbsPosGrandchild) {
   setBodyInnerHTML(
       " <div id='parent'><div id='absposparent'><div id='absposchild'>"
       " </div></div></div>"
@@ -32,7 +56,7 @@ TEST_F(PaintLayerTest, CompositedBoundsAbsPosGrandchild) {
             parentLayer->boundingBoxForCompositing());
 }
 
-TEST_F(PaintLayerTest, PaintingExtentReflection) {
+TEST_P(PaintLayerTest, PaintingExtentReflection) {
   setBodyInnerHTML(
       "<div id='target' style='background-color: blue; position: absolute;"
       "    width: 110px; height: 120px; top: 40px; left: 60px;"
@@ -46,7 +70,7 @@ TEST_F(PaintLayerTest, PaintingExtentReflection) {
       layer->paintingExtent(document().layoutView()->layer(), LayoutSize(), 0));
 }
 
-TEST_F(PaintLayerTest, PaintingExtentReflectionWithTransform) {
+TEST_P(PaintLayerTest, PaintingExtentReflectionWithTransform) {
   setBodyInnerHTML(
       "<div id='target' style='background-color: blue; position: absolute;"
       "    width: 110px; height: 120px; top: 40px; left: 60px;"
@@ -60,7 +84,60 @@ TEST_F(PaintLayerTest, PaintingExtentReflectionWithTransform) {
       layer->paintingExtent(document().layoutView()->layer(), LayoutSize(), 0));
 }
 
-TEST_F(PaintLayerTest, CompositedScrollingNoNeedsRepaint) {
+TEST_P(PaintLayerTest, ScrollsWithViewportRelativePosition) {
+  setBodyInnerHTML("<div id='target' style='position: relative'></div>");
+
+  PaintLayer* layer =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("target"))->layer();
+  EXPECT_FALSE(layer->scrollsWithViewport());
+}
+
+TEST_P(PaintLayerTest, ScrollsWithViewportFixedPosition) {
+  setBodyInnerHTML("<div id='target' style='position: fixed'></div>");
+
+  PaintLayer* layer =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("target"))->layer();
+  EXPECT_TRUE(layer->scrollsWithViewport());
+}
+
+TEST_P(PaintLayerTest, ScrollsWithViewportFixedPositionInsideTransform) {
+  setBodyInnerHTML(
+      "<div style='transform: translateZ(0)'>"

[pdr., 2016/12/06 04:38:51]

This isn't correct for spv2 because the viewport doesn't actually scroll. Can
you use the following where the fixed scroller is the transformed element?
"<div style='transform: translateZ(0); height: 10px; overflow: scroll;'>"
"  <div id='target' style='position: fixed;'></div>"
"  <div class='forcescroll' style='height: 5555px;'></div>"
"</div>"
"<div class='forcescroll' style='height: 5555px;'></div>"

Similarly for the other tests, please add "<div class='forcescroll'
style='height: 5555px;'></div>".

[chrishtr, 2016/12/06 23:56:06]

Added here, and also added another test without scrolling.

+      "  <div id='target' style='position: fixed'></div>"
+      "</div>");
+
+  PaintLayer* layer =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("target"))->layer();
+  EXPECT_FALSE(layer->scrollsWithViewport());
+}
+
+TEST_P(PaintLayerTest, ScrollsWithViewportStickyPosition) {
+  setBodyInnerHTML(
+      "<div style='transform: translateZ(0)'>"
+      "  <div id='target' style='position: sticky'></div>"
+      "</div>");
+
+  PaintLayer* layer =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("target"))->layer();
+  EXPECT_TRUE(layer->scrollsWithViewport());
+}
+
+TEST_P(PaintLayerTest, ScrollsWithViewportStickyPositionInsideScroller) {
+  setBodyInnerHTML(
+      "<div style='overflow:scroll; width: 100px; height: 100px;'>"
+      "  <div id='target' style='position: sticky'></div>"
+      "  <div style='width: 50px; height: 1000px;'></div>"
+      "</div>");
+
+  PaintLayer* layer =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("target"))->layer();
+  EXPECT_FALSE(layer->scrollsWithViewport());
+}
+
+TEST_P(PaintLayerTest, CompositedScrollingNoNeedsRepaint) {

[pdr., 2016/12/06 04:38:51]

Nit: Can you file a bug for this and include it here (similarly, for the todo in
CompositedBoundsAbsPosGrandchild)?
// TODO(chrishtr, crbug.com/90210): Despline the spv2 frobinator in the b-tree
hive.

Nit²: CompositedScrollingNoNeedsRepaint -> CompositedScrollingDoesNotNeedRepaint

+  if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+    return;
+
   enableCompositing();
   setBodyInnerHTML(
       "<div id='scroll' style='width: 100px; height: 100px; overflow: scroll;"
@@ -87,7 +164,7 @@ TEST_F(PaintLayerTest, CompositedScrollingNoNeedsRepaint) {
   document().view()->updateAllLifecyclePhases();
 }
 
-TEST_F(PaintLayerTest, NonCompositedScrollingNeedsRepaint) {
+TEST_P(PaintLayerTest, NonCompositedScrollingNeedsRepaint) {
   setBodyInnerHTML(
       "<div id='scroll' style='width: 100px; height: 100px; overflow: scroll'>"
       "  <div id='content' style='position: relative; background: blue;"
@@ -112,7 +189,7 @@ TEST_F(PaintLayerTest, NonCompositedScrollingNeedsRepaint) {
   document().view()->updateAllLifecyclePhases();
 }
 
-TEST_F(PaintLayerTest, HasNonIsolatedDescendantWithBlendMode) {
+TEST_P(PaintLayerTest, HasNonIsolatedDescendantWithBlendMode) {
   setBodyInnerHTML(
       "<div id='stacking-grandparent' style='isolation: isolate'>"
       "  <div id='stacking-parent' style='isolation: isolate'>"
@@ -140,7 +217,7 @@ TEST_F(PaintLayerTest, HasNonIsolatedDescendantWithBlendMode) {
   EXPECT_TRUE(parent->hasVisibleDescendant());
 }
 
-TEST_F(PaintLayerTest, HasDescendantWithClipPath) {
+TEST_P(PaintLayerTest, HasDescendantWithClipPath) {
   setBodyInnerHTML(
       "<div id='parent' style='position:relative'>"
       "  <div id='clip-path' style='clip-path: circle(50px at 0 100px)'>"
@@ -158,7 +235,7 @@ TEST_F(PaintLayerTest, HasDescendantWithClipPath) {
   EXPECT_TRUE(parent->hasVisibleDescendant());
 }
 
-TEST_F(PaintLayerTest, HasVisibleDescendant) {
+TEST_P(PaintLayerTest, HasVisibleDescendant) {
   enableCompositing();
   setBodyInnerHTML(
       "<div id='invisible' style='position:relative'>"