Optimize offscreen animation: don't update paint properties/visual rects

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2821323002
Cr-Commit-Position: refs/heads/master@{#468081}

third_party/WebKit/Source/core/layout/LayoutBox.cpp

@@ -1756,7 +1756,7 @@ void LayoutBox::PaintMask(const PaintInfo& paint_info,
 }
 
 void LayoutBox::ImageChanged(WrappedImagePtr image, const IntRect*) {
-  // TODO(chrishtr): support PaintInvalidationDelayedFull for animated border
+  // TODO(chrishtr): support kPaintInvalidationDelayedFull for animated border
   // images.
   if ((StyleRef().BorderImage().GetImage() &&
        StyleRef().BorderImage().GetImage()->Data() == image) ||
@@ -1878,14 +1878,11 @@ void LayoutBox::EnsureIsReadyForPaintInvalidation() {
     return;
 
   // Do regular full paint invalidation if the object with
-  // PaintInvalidationDelayedFull is onscreen.
-  if (IntersectsVisibleViewport()) {
+  // kPaintInvalidationDelayedFull is onscreen.
   // Conservatively assume the delayed paint invalidation was caused by
   // background image change.
   SetBackgroundChangedSinceLastPaintInvalidation();
-    SetShouldDoFullPaintInvalidationWithoutGeometryChange(
-        kPaintInvalidationFull);
-  }
+  SetShouldDoFullPaintInvalidationWithoutGeometryChange(kPaintInvalidationFull);
 }
 
 PaintInvalidationReason LayoutBox::InvalidatePaint(

third_party/WebKit/Source/core/layout/LayoutImage.cpp

@@ -170,10 +170,10 @@ void LayoutImage::InvalidatePaintAndMarkForLayoutIfNeeded() {
     return;
   }
 
-  if (ImageResource() && ImageResource()->MaybeAnimated())
-    SetShouldDoFullPaintInvalidation(kPaintInvalidationDelayedFull);
-  else
-    SetShouldDoFullPaintInvalidation(kPaintInvalidationFull);
+  SetShouldDoFullPaintInvalidationWithoutGeometryChange(
+      ImageResource() && ImageResource()->MaybeAnimated()
+          ? kPaintInvalidationDelayedFull
+          : kPaintInvalidationFull);
 
   // Tell any potential compositing layers that the image needs updating.
   ContentChanged(kImageChanged);

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

@@ -6,6 +6,8 @@
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutView.h"
 #include "core/paint/PaintLayer.h"
+#include "platform/graphics/GraphicsLayer.h"
+#include "platform/graphics/paint/RasterInvalidationTracking.h"
 #include "platform/testing/RuntimeEnabledFeaturesTestHelpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -20,6 +22,15 @@ class PaintInvalidationTest : public ::testing::WithParamInterface<bool>,
   PaintInvalidationTest()
       : ScopedRootLayerScrollingForTest(GetParam()),
         RenderingTest(SingleChildLocalFrameClient::Create()) {}
+
+ protected:
+  const RasterInvalidationTracking* GetRasterInvalidationTracking() const {
+    // TODO(wangxianzhu): Test SPv2.
+    return GetLayoutView()
+        .Layer()
+        ->GraphicsLayerBacking()
+        ->GetRasterInvalidationTracking();
+  }
 };
 
 INSTANTIATE_TEST_CASE_P(All, PaintInvalidationTest, ::testing::Bool());
@@ -153,6 +164,43 @@ TEST_P(PaintInvalidationTest, InvisibleTransformUnderFixedOnScroll) {
   GetDocument().View()->UpdateAllLifecyclePhases();
 }
 
+TEST_P(PaintInvalidationTest, DelayedFullPaintInvalidation) {
+  EnableCompositing();
+  SetBodyInnerHTML(
+      "<style>body { margin: 0 }</style>"
+      "<div style='height: 4000px'></div>"
+      "<div id='target' style='width: 100px; height: 100px; background: blue'>"
+      "</div>");
+
+  auto* target = GetLayoutObjectByElementId("target");
+  target->SetShouldDoFullPaintInvalidationWithoutGeometryChange(
+      kPaintInvalidationDelayedFull);
+  EXPECT_EQ(kPaintInvalidationDelayedFull,
+            target->FullPaintInvalidationReason());
+  EXPECT_FALSE(target->NeedsPaintOffsetAndVisualRectUpdate());
+
+  GetDocument().View()->SetTracksPaintInvalidations(true);
+  GetDocument().View()->UpdateAllLifecyclePhases();
+  EXPECT_EQ(nullptr, GetRasterInvalidationTracking());
+  EXPECT_EQ(kPaintInvalidationDelayedFull,
+            target->FullPaintInvalidationReason());
+  EXPECT_FALSE(target->NeedsPaintOffsetAndVisualRectUpdate());
+  GetDocument().View()->SetTracksPaintInvalidations(false);
+
+  GetDocument().View()->SetTracksPaintInvalidations(true);
+  // Scroll target into view.
+  GetDocument().domWindow()->scrollTo(0, 4000);
+  GetDocument().View()->UpdateAllLifecyclePhases();
+  const auto& raster_invalidations =
+      GetRasterInvalidationTracking()->tracked_raster_invalidations;
+  ASSERT_EQ(1u, raster_invalidations.size());
+  EXPECT_EQ(kPaintInvalidationNone, target->FullPaintInvalidationReason());
+  EXPECT_EQ(IntRect(0, 4000, 100, 100), raster_invalidations[0].rect);
+  EXPECT_EQ(kPaintInvalidationFull, raster_invalidations[0].reason);
+  EXPECT_FALSE(target->NeedsPaintOffsetAndVisualRectUpdate());
+  GetDocument().View()->SetTracksPaintInvalidations(false);
+};
+
 }  // namespace
 
 }  // namespace blink

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

@@ -510,7 +510,8 @@ void PaintInvalidator::InvalidatePaint(const LayoutObject& object,
 
 void PaintInvalidator::ProcessPendingDelayedPaintInvalidations() {
   for (auto target : pending_delayed_paint_invalidations_) {
-    target->GetMutableForPainting().SetShouldDoFullPaintInvalidation(
+    target->GetMutableForPainting()
+        .SetShouldDoFullPaintInvalidationWithoutGeometryChange(
             kPaintInvalidationDelayedFull);
   }
 }