cc: Implement PictureImageLayer::PaintContentsToDisplayList

This allows PictureImageLayers to be rendered when running with
--enable-slimming-paint.

BUG=448447

Review URL: https://codereview.chromium.org/853463004

Cr-Commit-Position: refs/heads/master@{#311491}

cc/BUILD.gn

@@ -756,6 +756,7 @@ test("cc_unittests") {
     "layers/nine_patch_layer_unittest.cc",
     "layers/painted_scrollbar_layer_impl_unittest.cc",
     "layers/picture_image_layer_impl_unittest.cc",
+    "layers/picture_image_layer_unittest.cc",
     "layers/picture_layer_impl_unittest.cc",
     "layers/picture_layer_unittest.cc",
     "layers/render_surface_unittest.cc",

cc/cc_tests.gyp

@@ -43,6 +43,7 @@
       'layers/nine_patch_layer_unittest.cc',
       'layers/painted_scrollbar_layer_impl_unittest.cc',
       'layers/picture_image_layer_impl_unittest.cc',
+      'layers/picture_image_layer_unittest.cc',
       'layers/picture_layer_impl_unittest.cc',
       'layers/picture_layer_unittest.cc',
       'layers/render_surface_unittest.cc',

cc/layers/picture_image_layer.cc

@@ -5,7 +5,10 @@
 #include "cc/layers/picture_image_layer.h"
 
 #include "cc/layers/picture_image_layer_impl.h"
+#include "cc/resources/drawing_display_item.h"
 #include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkPictureRecorder.h"
+#include "ui/gfx/skia_util.h"
 
 namespace cc {
 
@@ -63,8 +66,16 @@ void PictureImageLayer::PaintContents(
 scoped_refptr<DisplayItemList> PictureImageLayer::PaintContentsToDisplayList(
     const gfx::Rect& clip,
     GraphicsContextStatus gc_status) {
-  NOTIMPLEMENTED();
-  return DisplayItemList::Create();
+  scoped_refptr<DisplayItemList> display_item_list = DisplayItemList::Create();
+
+  SkPictureRecorder recorder;
+  SkCanvas* canvas = recorder.beginRecording(gfx::RectToSkRect(clip));
+  PaintContents(canvas, clip, gc_status);
+
+  skia::RefPtr<SkPicture> picture = skia::AdoptRef(recorder.endRecording());
+  display_item_list->AppendItem(
+      DrawingDisplayItem::Create(picture, gfx::Point()));
+  return display_item_list;
 }
 
 bool PictureImageLayer::FillsBoundsCompletely() const {

cc/layers/picture_image_layer_unittest.cc

+// Copyright 2015 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 "cc/layers/picture_image_layer.h"
+
+#include "cc/resources/display_item.h"
+#include "cc/test/skia_common.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkColor.h"
+
+namespace cc {
+namespace {
+
+TEST(PictureImageLayerTest, PaintContentsToDisplayList) {
+  scoped_refptr<PictureImageLayer> layer = PictureImageLayer::Create();
+  gfx::Rect layer_rect(200, 200);
+
+  SkBitmap image_bitmap;
+  unsigned char image_pixels[4 * 200 * 200] = {0};
+  SkImageInfo info =
+      SkImageInfo::MakeN32Premul(layer_rect.width(), layer_rect.height());
+  image_bitmap.installPixels(info, image_pixels, info.minRowBytes());
+  SkCanvas image_canvas(image_bitmap);
+  image_canvas.clear(SK_ColorRED);
+  SkPaint blue_paint;
+  blue_paint.setColor(SK_ColorBLUE);
+  image_canvas.drawRectCoords(0.f, 0.f, 100.f, 100.f, blue_paint);
+  image_canvas.drawRectCoords(100.f, 100.f, 200.f, 200.f, blue_paint);
+
+  layer->SetBitmap(image_bitmap);
+  layer->SetBounds(gfx::Size(layer_rect.width(), layer_rect.height()));
+
+  scoped_refptr<DisplayItemList> display_list =
+      layer->PaintContentsToDisplayList(
+          layer_rect, ContentLayerClient::GRAPHICS_CONTEXT_ENABLED);
+  unsigned char actual_pixels[4 * 200 * 200] = {0};
+  DrawDisplayList(actual_pixels, layer_rect, display_list);
+
+  EXPECT_EQ(0, memcmp(actual_pixels, image_pixels, 4 * 200 * 200));
+}
+
+}  // namespace
+}  // namespace cc