Setup classes for native paintworklet

This CL creates classes to build the infra of native paint worklet.
Specifically, we create a NativePaintWorklet class, and when
we paint the background color, we ask the NativePaintWorklet
to do the paint. Because NativePaintWorklet lives under the
modules/ and paint part is in core/, we need some other classes
to be there so that the paint can call NativePaintWorklet APIs.

Design doc here:
https://docs.google.com/document/d/1usCnwWs8HsH5FU_185q6MsrZehFmpl5QgbbB4pvHIjI/edit

Bug: 1138997
Change-Id: Ifdabf3ce5226ee4cacac03eec46029e74c3fa9c6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2464428Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#820663}

third_party/blink/renderer/core/css/build.gni

@@ -380,6 +380,8 @@ blink_core_sources_css = [
   "media_values_dynamic.h",
   "media_values_initial_viewport.cc",
   "media_values_initial_viewport.h",
+  "native_paint_image_generator.cc",
+  "native_paint_image_generator.h",
   "offscreen_font_selector.cc",
   "offscreen_font_selector.h",
   "page_rule_collector.cc",

third_party/blink/renderer/core/css/native_paint_image_generator.cc

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "third_party/blink/renderer/core/css/native_paint_image_generator.h"
+
+namespace blink {
+
+namespace {
+
+NativePaintImageGenerator::NativePaintImageGeneratorCreateFunction
+    g_create_function = nullptr;
+
+}  // namespace
+
+// static
+void NativePaintImageGenerator::Init(
+    NativePaintImageGeneratorCreateFunction create_function) {
+  DCHECK(!g_create_function);
+  g_create_function = create_function;
+}
+
+// static
+std::unique_ptr<NativePaintImageGenerator> NativePaintImageGenerator::Create() {
+  DCHECK(g_create_function);
+  return g_create_function();
+}
+
+NativePaintImageGenerator::~NativePaintImageGenerator() = default;
+
+}  // namespace blink

third_party/blink/renderer/core/css/native_paint_image_generator.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_CSS_NATIVE_PAINT_IMAGE_GENERATOR_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_NATIVE_PAINT_IMAGE_GENERATOR_H_
+
+#include "third_party/blink/renderer/core/core_export.h"
+#include "third_party/blink/renderer/platform/geometry/float_size.h"
+#include "third_party/skia/include/core/SkColor.h"
+
+namespace blink {
+
+class Image;
+
+class CORE_EXPORT NativePaintImageGenerator {
+ public:
+  static std::unique_ptr<NativePaintImageGenerator> Create();
+  virtual ~NativePaintImageGenerator();
+
+  typedef std::unique_ptr<NativePaintImageGenerator> (
+      *NativePaintImageGeneratorCreateFunction)();
+  static void Init(NativePaintImageGeneratorCreateFunction);
+
+  virtual scoped_refptr<Image> Paint(const FloatSize& container_size,
+                                     SkColor color) = 0;
+};
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_CSS_NATIVE_PAINT_IMAGE_GENERATOR_H_

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

@@ -5,6 +5,7 @@
 #include "third_party/blink/renderer/core/paint/box_painter_base.h"
 
 #include "base/optional.h"
+#include "third_party/blink/renderer/core/css/native_paint_image_generator.h"
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/dom/node_computed_style.h"
 #include "third_party/blink/renderer/core/frame/settings.h"
@@ -318,6 +319,9 @@ BoxPainterBase::FillLayerInfo::FillLayerInfo(
   should_paint_color =
       is_bottom_layer && color.Alpha() &&
       (!should_paint_image || !layer.ImageOccludesNextLayers(doc, style));
+  should_paint_color_with_paint_worklet_image =
+      should_paint_color &&
+      RuntimeEnabledFeatures::CompositeBGColorAnimationEnabled();
 }
 
 namespace {
@@ -478,6 +482,21 @@ void DrawTiledBackground(GraphicsContext& context,
                          respect_orientation);
 }
 
+void FillRectWithPaintWorklet(const BoxPainterBase::FillLayerInfo& info,
+                              Node* node,
+                              const FloatRoundedRect& dest_rect,
+                              GraphicsContext& context) {
+  FloatRect src_rect = dest_rect.Rect();
+  std::unique_ptr<NativePaintImageGenerator> generator =
+      NativePaintImageGenerator::Create();
+  scoped_refptr<Image> paint_worklet_image =
+      generator->Paint(src_rect.Size(), SkColor(info.color));
+  context.DrawImageRRect(
+      paint_worklet_image.get(), Image::kSyncDecode, dest_rect, src_rect,
+      node && node->ComputedStyleRef().HasFilterInducingProperty(),
+      SkBlendMode::kSrcOver, info.respect_image_orientation);
+}
+
 inline bool PaintFastBottomLayer(Node* node,
                                  const PaintInfo& paint_info,
                                  const BoxPainterBase::FillLayerInfo& info,
@@ -563,8 +582,13 @@ inline bool PaintFastBottomLayer(Node* node,
   }
 
   // Paint the color if needed.
-  if (info.should_paint_color)
-    context.FillRoundedRect(color_border, info.color);
+  if (info.should_paint_color) {
+    if (info.should_paint_color_with_paint_worklet_image) {
+      FillRectWithPaintWorklet(info, node, color_border, context);
+    } else {
+      context.FillRoundedRect(color_border, info.color);
+    }
+  }
 
   // Paint the image if needed.
   if (!info.should_paint_image || !image || image_tile.IsEmpty())
@@ -737,7 +761,12 @@ void PaintFillLayerBackground(GraphicsContext& context,
   // painting area.
   if (info.is_bottom_layer && info.color.Alpha() && info.should_paint_color) {
     IntRect background_rect(PixelSnappedIntRect(scrolled_paint_rect));
-    context.FillRect(background_rect, info.color);
+    if (info.should_paint_color_with_paint_worklet_image) {
+      FillRectWithPaintWorklet(info, node, FloatRoundedRect(background_rect),
+                               context);
+    } else {
+      context.FillRect(background_rect, info.color);
+    }
   }
 
   // No progressive loading of the background image.

third_party/blink/renderer/core/paint/box_painter_base.h

@@ -134,6 +134,9 @@ class BoxPainterBase {
     bool is_rounded_fill;
     bool should_paint_image;
     bool should_paint_color;
+    // True if we paint background color off main thread, design doc here:
+    // https://docs.google.com/document/d/1usCnwWs8HsH5FU_185q6MsrZehFmpl5QgbbB4pvHIjI/edit
+    bool should_paint_color_with_paint_worklet_image;
   };
 
  protected:

third_party/blink/renderer/modules/csspaint/BUILD.gn

@@ -14,6 +14,10 @@ blink_modules_sources("csspaint") {
     "css_paint_worklet.h",
     "document_paint_definition.cc",
     "document_paint_definition.h",
+    "native_paint_image_generator_impl.cc",
+    "native_paint_image_generator_impl.h",
+    "native_paint_worklet.cc",
+    "native_paint_worklet.h",
     "paint_rendering_context_2d.cc",
     "paint_rendering_context_2d.h",
     "paint_size.h",

third_party/blink/renderer/modules/csspaint/native_paint_image_generator_impl.cc

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "third_party/blink/renderer/modules/csspaint/native_paint_image_generator_impl.h"
+
+#include "third_party/blink/renderer/modules/csspaint/native_paint_worklet.h"
+#include "third_party/blink/renderer/platform/graphics/image.h"
+
+namespace blink {
+
+std::unique_ptr<NativePaintImageGenerator>
+NativePaintImageGeneratorImpl::Create() {
+  std::unique_ptr<NativePaintWorklet> native_paint_worklet =
+      std::make_unique<NativePaintWorklet>();
+
+  DCHECK(native_paint_worklet);
+  std::unique_ptr<NativePaintImageGeneratorImpl> generator =
+      std::make_unique<NativePaintImageGeneratorImpl>(
+          std::move(native_paint_worklet));
+
+  return generator;
+}
+
+NativePaintImageGeneratorImpl::NativePaintImageGeneratorImpl(
+    std::unique_ptr<NativePaintWorklet> native_paint_worklet)
+    : native_paint_worklet_(std::move(native_paint_worklet)) {}
+
+NativePaintImageGeneratorImpl::~NativePaintImageGeneratorImpl() = default;
+
+scoped_refptr<Image> NativePaintImageGeneratorImpl::Paint(
+    const FloatSize& container_size,
+    SkColor color) {
+  return native_paint_worklet_->Paint(container_size, color);
+}
+
+}  // namespace blink

third_party/blink/renderer/modules/csspaint/native_paint_image_generator_impl.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_CSSPAINT_NATIVE_PAINT_IMAGE_GENERATOR_IMPL_H_
+#define THIRD_PARTY_BLINK_RENDERER_MODULES_CSSPAINT_NATIVE_PAINT_IMAGE_GENERATOR_IMPL_H_
+
+#include "third_party/blink/renderer/core/css/native_paint_image_generator.h"
+#include "third_party/blink/renderer/modules/modules_export.h"
+#include "third_party/blink/renderer/platform/geometry/float_size.h"
+#include "v8/include/v8.h"
+
+namespace blink {
+
+class Image;
+class NativePaintWorklet;
+
+class MODULES_EXPORT NativePaintImageGeneratorImpl final
+    : public NativePaintImageGenerator {
+ public:
+  static std::unique_ptr<NativePaintImageGenerator> Create();
+
+  explicit NativePaintImageGeneratorImpl(std::unique_ptr<NativePaintWorklet>);
+  ~NativePaintImageGeneratorImpl() override;
+
+  // The |container_size| is without subpixel snapping.
+  scoped_refptr<Image> Paint(const FloatSize& container_size,
+                             SkColor color) final;
+
+ private:
+  std::unique_ptr<NativePaintWorklet> native_paint_worklet_;
+};
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_CSSPAINT_NATIVE_PAINT_IMAGE_GENERATOR_IMPL_H_

third_party/blink/renderer/modules/csspaint/native_paint_worklet.cc

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "third_party/blink/renderer/modules/csspaint/native_paint_worklet.h"
+
+#include "third_party/blink/renderer/modules/csspaint/paint_rendering_context_2d.h"
+#include "third_party/blink/renderer/platform/graphics/paint_generated_image.h"
+
+namespace blink {
+
+NativePaintWorklet::NativePaintWorklet() = default;
+
+NativePaintWorklet::~NativePaintWorklet() = default;
+
+scoped_refptr<Image> NativePaintWorklet::Paint(const FloatSize& container_size,
+                                               SkColor color) {
+  PaintRenderingContext2DSettings* context_settings =
+      PaintRenderingContext2DSettings::Create();
+  auto* rendering_context = MakeGarbageCollected<PaintRenderingContext2D>(
+      RoundedIntSize(container_size), context_settings, 1, 1);
+  rendering_context->GetPaintCanvas()->drawColor(color);
+  sk_sp<PaintRecord> paint_record = rendering_context->GetRecord();
+  if (!paint_record)
+    return nullptr;
+  return PaintGeneratedImage::Create(paint_record, container_size);
+}
+
+}  // namespace blink

third_party/blink/renderer/modules/csspaint/native_paint_worklet.h

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_CSSPAINT_NATIVE_PAINT_WORKLET_H_
+#define THIRD_PARTY_BLINK_RENDERER_MODULES_CSSPAINT_NATIVE_PAINT_WORKLET_H_
+
+#include <memory>
+
+#include "base/macros.h"
+#include "third_party/blink/renderer/modules/modules_export.h"
+#include "third_party/blink/renderer/platform/geometry/float_size.h"
+#include "third_party/blink/renderer/platform/graphics/image.h"
+#include "third_party/skia/include/core/SkColor.h"
+
+namespace blink {
+
+class MODULES_EXPORT NativePaintWorklet {
+ public:
+  explicit NativePaintWorklet();
+  virtual ~NativePaintWorklet();
+
+  // The |container_size| is without subpixel snapping.
+  scoped_refptr<Image> Paint(const FloatSize& container_size, SkColor color);
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NativePaintWorklet);
+};
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_CSSPAINT_NATIVE_PAINT_WORKLET_H_

third_party/blink/renderer/modules/modules_initializer.cc

@@ -17,6 +17,7 @@
 #include "third_party/blink/public/web/web_view_client.h"
 #include "third_party/blink/renderer/bindings/modules/v8/module_bindings_initializer.h"
 #include "third_party/blink/renderer/core/css/css_paint_image_generator.h"
+#include "third_party/blink/renderer/core/css/native_paint_image_generator.h"
 #include "third_party/blink/renderer/core/dom/context_features_client_impl.h"
 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/editing/suggestion/text_suggestion_backend_impl.h"
@@ -42,6 +43,7 @@
 #include "third_party/blink/renderer/modules/canvas/imagebitmap/image_bitmap_rendering_context.h"
 #include "third_party/blink/renderer/modules/canvas/offscreencanvas2d/offscreen_canvas_rendering_context_2d.h"
 #include "third_party/blink/renderer/modules/csspaint/css_paint_image_generator_impl.h"
+#include "third_party/blink/renderer/modules/csspaint/native_paint_image_generator_impl.h"
 #include "third_party/blink/renderer/modules/device_orientation/device_motion_controller.h"
 #include "third_party/blink/renderer/modules/device_orientation/device_orientation_absolute_controller.h"
 #include "third_party/blink/renderer/modules/device_orientation/device_orientation_controller.h"
@@ -123,6 +125,7 @@ void ModulesInitializer::Initialize() {
   DraggedIsolatedFileSystem::Init(
       DraggedIsolatedFileSystemImpl::PrepareForDataObject);
   CSSPaintImageGenerator::Init(CSSPaintImageGeneratorImpl::Create);
+  NativePaintImageGenerator::Init(NativePaintImageGeneratorImpl::Create);
   WebDatabaseHost::GetInstance().Init();
   MediaSourceRegistryImpl::Init();
 

third_party/blink/web_tests/VirtualTestSuites

@@ -178,6 +178,11 @@
     "args": ["--mse-audio-buffer-size-limit-mb=1",
              "--mse-video-buffer-size-limit-mb=1"]
   },
+  {
+    "prefix": "composite-bgcolor-animation",
+    "bases": ["external/wpt/css/composite-bgcolor-animation"],
+    "args": ["--enable-blink-features=CompositeBGColorAnimation"]
+  },
   {
     "prefix": "composite-after-paint",
     "bases": ["compositing",

third_party/blink/web_tests/external/wpt/css/composite-bgcolor-animation/bg-color-with-gradient-ref.html

+<!DOCTYPE html>
+<body>
+  <canvas id="canvas" width="100" height="100"></canvas>
+</body>
+<script>
+  var canvas = document.getElementById('canvas');
+  var ctx = canvas.getContext('2d');
+  var grad = ctx.createLinearGradient(0, 0, 0, 100);
+  grad.addColorStop(0, 'red');
+  grad.addColorStop(1, 'black');
+  ctx.fillStyle = grad;
+  ctx.fillRect(0, 0, 100, 100);
+</script>

third_party/blink/web_tests/external/wpt/css/composite-bgcolor-animation/bg-color-with-gradient.html

+<!DOCTYPE html>
+<link rel="help" href="https://drafts.csswg.org/css-backgrounds-3/#background-color">
+<link rel="match" href="bg-color-with-gradient-ref.html">
+<div style="width: 100px; height: 100px; background: linear-gradient(red, black); background-color: green;"></div>

third_party/blink/web_tests/external/wpt/css/composite-bgcolor-animation/simple-bg-color-ref.html

+<!DOCTYPE html>
+<body>
+  <canvas id="canvas" width="200" height="400"></canvas>
+</body>
+<script>
+  var canvas = document.getElementById('canvas');
+  var ctx = canvas.getContext('2d');
+  ctx.fillStyle = 'green';
+  ctx.fillRect(0, 0, 100, 150);
+  ctx.fillStyle = 'red';
+  ctx.fillRect(0, 150, 200, 250);
+</script>

third_party/blink/web_tests/external/wpt/css/composite-bgcolor-animation/simple-bg-color.html

+<!DOCTYPE html>
+<link rel="help" href="https://drafts.csswg.org/css-backgrounds-3/#background-color">
+<link rel="match" href="simple-bg-color-ref.html">
+<style>
+.box1 {
+  width: 100px;
+  height: 150px;
+  background-color: green;
+}
+.box2 {
+  width: 200px;
+  height: 250px;
+  background-color: red;
+}
+</style>
+<body>
+  <div class='box1'></div>
+  <div class='box2'></div>
+</body>

third_party/blink/web_tests/virtual/composite-bgcolor-animation/external/wpt/css/composite-bgcolor-animation/README.txt

+# This suite runs the test in external/wpt/css/composite-bg-color-animation with
+# --enable-blink-features=CompositeBGColorAnimation