cc: Use a ListContainer for DisplayItemList to reduce allocations.

cc/resources/display_item_list_unittest.cc

 // Copyright 2014 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/resources/display_item_list.h"
 
 #include <vector>
 
 #include "cc/output/filter_operation.h"
 #include "cc/output/filter_operations.h"
@@ skipping 30 matching lines @@
       DisplayItemList::Create(layer_rect, use_cached_picture);
 
   gfx::PointF offset(8.f, 9.f);
   gfx::RectF recording_rect(offset, layer_rect.size());
   canvas = skia::SharePtr(
       recorder.beginRecording(gfx::RectFToSkRect(recording_rect)));
   canvas->translate(offset.x(), offset.y());
   canvas->drawRectCoords(0.f, 0.f, 60.f, 60.f, red_paint);
   canvas->drawRectCoords(50.f, 50.f, 75.f, 75.f, blue_paint);
   picture = skia::AdoptRef(recorder.endRecordingAsPicture());
-  list->AppendItem(DrawingDisplayItem::Create(picture));
+  auto* item = list->CreateAndAppendItem<DrawingDisplayItem>();
+  item->SetNew(picture);
+  list->ProcessAppendedItems();
   list->CreateAndCacheSkPicture();
   DrawDisplayList(pixels, layer_rect, list);
 
   SkBitmap expected_bitmap;
   unsigned char expected_pixels[4 * 100 * 100] = {0};
   SkImageInfo info =
       SkImageInfo::MakeN32Premul(layer_rect.width(), layer_rect.height());
   expected_bitmap.installPixels(info, expected_pixels, info.minRowBytes());
   SkCanvas expected_canvas(expected_bitmap);
   expected_canvas.clipRect(gfx::RectToSkRect(layer_rect));
@@ skipping 21 matching lines @@
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(layer_rect, use_cached_picture);
 
   gfx::PointF first_offset(8.f, 9.f);
   gfx::RectF first_recording_rect(first_offset, layer_rect.size());
   canvas = skia::SharePtr(
       recorder.beginRecording(gfx::RectFToSkRect(first_recording_rect)));
   canvas->translate(first_offset.x(), first_offset.y());
   canvas->drawRectCoords(0.f, 0.f, 60.f, 60.f, red_paint);
   picture = skia::AdoptRef(recorder.endRecordingAsPicture());
-  list->AppendItem(DrawingDisplayItem::Create(picture));
+  auto* item1 = list->CreateAndAppendItem<DrawingDisplayItem>();
+  item1->SetNew(picture.Pass());
 
   gfx::Rect clip_rect(60, 60, 10, 10);
-  list->AppendItem(ClipDisplayItem::Create(clip_rect, std::vector<SkRRect>()));
+  auto* item2 = list->CreateAndAppendItem<ClipDisplayItem>();
+  item2->SetNew(clip_rect, std::vector<SkRRect>());
 
   gfx::PointF second_offset(2.f, 3.f);
   gfx::RectF second_recording_rect(second_offset, layer_rect.size());
   canvas = skia::SharePtr(
       recorder.beginRecording(gfx::RectFToSkRect(second_recording_rect)));
   canvas->translate(second_offset.x(), second_offset.y());
   canvas->drawRectCoords(50.f, 50.f, 75.f, 75.f, blue_paint);
   picture = skia::AdoptRef(recorder.endRecordingAsPicture());
-  list->AppendItem(DrawingDisplayItem::Create(picture));
+  auto* item3 = list->CreateAndAppendItem<DrawingDisplayItem>();
+  item3->SetNew(picture.Pass());
 
-  list->AppendItem(EndClipDisplayItem::Create());
+  list->CreateAndAppendItem<EndClipDisplayItem>();
+  list->ProcessAppendedItems();
   list->CreateAndCacheSkPicture();
 
   DrawDisplayList(pixels, layer_rect, list);
 
   SkBitmap expected_bitmap;
   unsigned char expected_pixels[4 * 100 * 100] = {0};
   SkImageInfo info =
       SkImageInfo::MakeN32Premul(layer_rect.width(), layer_rect.height());
   expected_bitmap.installPixels(info, expected_pixels, info.minRowBytes());
   SkCanvas expected_canvas(expected_bitmap);
@@ skipping 23 matching lines @@
   scoped_refptr<DisplayItemList> list =
       DisplayItemList::Create(layer_rect, use_cached_picture);
 
   gfx::PointF first_offset(8.f, 9.f);
   gfx::RectF first_recording_rect(first_offset, layer_rect.size());
   canvas = skia::SharePtr(
       recorder.beginRecording(gfx::RectFToSkRect(first_recording_rect)));
   canvas->translate(first_offset.x(), first_offset.y());
   canvas->drawRectCoords(0.f, 0.f, 60.f, 60.f, red_paint);
   picture = skia::AdoptRef(recorder.endRecordingAsPicture());
-  list->AppendItem(DrawingDisplayItem::Create(picture));
+  auto* item1 = list->CreateAndAppendItem<DrawingDisplayItem>();
+  item1->SetNew(picture);
 
   gfx::Transform transform;
   transform.Rotate(45.0);
-  list->AppendItem(TransformDisplayItem::Create(transform));
+  auto* item2 = list->CreateAndAppendItem<TransformDisplayItem>();
+  item2->SetNew(transform);
 
   gfx::PointF second_offset(2.f, 3.f);
   gfx::RectF second_recording_rect(second_offset, layer_rect.size());
   canvas = skia::SharePtr(
       recorder.beginRecording(gfx::RectFToSkRect(second_recording_rect)));
   canvas->translate(second_offset.x(), second_offset.y());
   canvas->drawRectCoords(50.f, 50.f, 75.f, 75.f, blue_paint);
   picture = skia::AdoptRef(recorder.endRecordingAsPicture());
-  list->AppendItem(DrawingDisplayItem::Create(picture));
+  auto* item3 = list->CreateAndAppendItem<DrawingDisplayItem>();
+  item3->SetNew(picture);
 
-  list->AppendItem(EndTransformDisplayItem::Create());
+  list->CreateAndAppendItem<EndTransformDisplayItem>();
+  list->ProcessAppendedItems();
   list->CreateAndCacheSkPicture();
 
   DrawDisplayList(pixels, layer_rect, list);
 
   SkBitmap expected_bitmap;
   unsigned char expected_pixels[4 * 100 * 100] = {0};
   SkImageInfo info =
       SkImageInfo::MakeN32Premul(layer_rect.width(), layer_rect.height());
   expected_bitmap.installPixels(info, expected_pixels, info.minRowBytes());
   SkCanvas expected_canvas(expected_bitmap);
@@ skipping 31 matching lines @@
   // translating |dst| after it is computed by computeFastBounds, rather than
   // translating |src| before it provided to computedFastBounds) can cause
   // incorrect clipping of filter output. To test for this, we include an
   // SkBitmapSource filter in |filters|. Here, |src| is |filter_bounds|, defined
   // below.
   skia::RefPtr<SkImageFilter> image_filter =
       skia::AdoptRef(SkBitmapSource::Create(source_bitmap));
   filters.Append(FilterOperation::CreateReferenceFilter(image_filter));
   filters.Append(FilterOperation::CreateBrightnessFilter(0.5f));
   gfx::RectF filter_bounds(10.f, 10.f, 50.f, 50.f);
-  list->AppendItem(FilterDisplayItem::Create(filters, filter_bounds));
-  list->AppendItem(EndFilterDisplayItem::Create());
+  auto* item = list->CreateAndAppendItem<FilterDisplayItem>();
+  item->SetNew(filters, filter_bounds);
+  list->CreateAndAppendItem<EndFilterDisplayItem>();
+  list->ProcessAppendedItems();
   list->CreateAndCacheSkPicture();
 
   DrawDisplayList(pixels, layer_rect, list);
 
   SkBitmap expected_bitmap;
   unsigned char expected_pixels[4 * 100 * 100] = {0};
   SkPaint paint;
   paint.setColor(SkColorSetRGB(64, 64, 64));
   SkImageInfo info =
       SkImageInfo::MakeN32Premul(layer_rect.width(), layer_rect.height());
@@ skipping 21 matching lines @@
   bool use_cached_picture = false;
   scoped_refptr<DisplayItemList> list_without_caching =
       DisplayItemList::Create(layer_rect, use_cached_picture);
 
   canvas = skia::SharePtr(
       recorder.beginRecording(gfx::RectFToSkRect(recording_rect)));
   canvas->translate(offset.x(), offset.y());
   canvas->drawRectCoords(0.f, 0.f, 60.f, 60.f, red_paint);
   canvas->drawRectCoords(50.f, 50.f, 75.f, 75.f, blue_paint);
   picture = skia::AdoptRef(recorder.endRecordingAsPicture());
-  list_without_caching->AppendItem(DrawingDisplayItem::Create(picture));
+  auto* item1 = list_without_caching->CreateAndAppendItem<DrawingDisplayItem>();
+  item1->SetNew(picture);
+  list_without_caching->ProcessAppendedItems();
   DrawDisplayList(pixels, layer_rect, list_without_caching);
 
   unsigned char expected_pixels[4 * 100 * 100] = {0};
   use_cached_picture = true;
   scoped_refptr<DisplayItemList> list_with_caching =
       DisplayItemList::Create(layer_rect, use_cached_picture);
-  list_with_caching->AppendItem(DrawingDisplayItem::Create(picture));
+  auto* item2 = list_with_caching->CreateAndAppendItem<DrawingDisplayItem>();
+  item2->SetNew(picture);
+  list_with_caching->ProcessAppendedItems();
   list_with_caching->CreateAndCacheSkPicture();
   DrawDisplayList(expected_pixels, layer_rect, list_with_caching);
 
   EXPECT_EQ(0, memcmp(pixels, expected_pixels, 4 * 100 * 100));
 }
 
 TEST(DisplayItemListTest, PictureMemoryUsage) {
   scoped_refptr<DisplayItemList> list;
   size_t memory_usage;
 
   // Make an SkPicture whose size is known.
   gfx::Rect layer_rect(100, 100);
   SkPictureRecorder recorder;
   SkPaint blue_paint;
   blue_paint.setColor(SK_ColorBLUE);
   SkCanvas* canvas = recorder.beginRecording(gfx::RectFToSkRect(layer_rect));
   for (int i = 0; i < 100; i++)
     canvas->drawPaint(blue_paint);
   skia::RefPtr<SkPicture> picture =
       skia::AdoptRef(recorder.endRecordingAsPicture());
   size_t picture_size = SkPictureUtils::ApproximateBytesUsed(picture.get());
   ASSERT_GE(picture_size, 100 * sizeof(SkPaint));
   ASSERT_LE(picture_size, 200 * sizeof(SkPaint));
 
   // Using a cached picture, we should get about the right size.
   list = DisplayItemList::Create(layer_rect, true);
-  list->AppendItem(DrawingDisplayItem::Create(picture));
+  auto* item = list->CreateAndAppendItem<DrawingDisplayItem>();
+  item->SetNew(picture);
+  list->ProcessAppendedItems();
   list->CreateAndCacheSkPicture();
   memory_usage = list->PictureMemoryUsage();
   EXPECT_GE(memory_usage, picture_size);
   EXPECT_LE(memory_usage, 2 * picture_size);
 
   // Using no cached picture, we should still get the right size.
   list = DisplayItemList::Create(layer_rect, false);
-  list->AppendItem(DrawingDisplayItem::Create(picture));
+  item = list->CreateAndAppendItem<DrawingDisplayItem>();
+  item->SetNew(picture);
+  list->ProcessAppendedItems();
   memory_usage = list->PictureMemoryUsage();
   EXPECT_GE(memory_usage, picture_size);
   EXPECT_LE(memory_usage, 2 * picture_size);
 
   // To avoid double counting, we expect zero size to be computed if both the
   // picture and items are retained (currently this only happens due to certain
   // categories being traced).
   list = new DisplayItemList(layer_rect, true, true);
-  list->AppendItem(DrawingDisplayItem::Create(picture));
+  item = list->CreateAndAppendItem<DrawingDisplayItem>();
+  item->SetNew(picture);
+  list->ProcessAppendedItems();
   list->CreateAndCacheSkPicture();
   memory_usage = list->PictureMemoryUsage();
   EXPECT_EQ(static_cast<size_t>(0), memory_usage);
 }
 
 }  // namespace cc