Update from https://crrev.com/316786

cc/resources/display_item_list_unittest.cc

Index: cc/resources/display_item_list_unittest.cc
diff --git a/cc/resources/display_item_list_unittest.cc b/cc/resources/display_item_list_unittest.cc
index d6455a2f953be583c5ca721408bebe4c67be67c3..ddf2cb706f46de74bd3b41ceed067dd8a73c501a 100644
--- a/cc/resources/display_item_list_unittest.cc
+++ b/cc/resources/display_item_list_unittest.cc
@@ -6,8 +6,11 @@
 
 #include <vector>
 
+#include "cc/output/filter_operation.h"
+#include "cc/output/filter_operations.h"
 #include "cc/resources/clip_display_item.h"
 #include "cc/resources/drawing_display_item.h"
+#include "cc/resources/filter_display_item.h"
 #include "cc/resources/transform_display_item.h"
 #include "cc/test/skia_common.h"
 #include "skia/ext/refptr.h"
@@ -16,6 +19,7 @@
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
+#include "third_party/skia/include/effects/SkBitmapSource.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
@@ -162,5 +166,50 @@ TEST(DisplayItemListTest, TransformItem) {
   EXPECT_EQ(0, memcmp(pixels, expected_pixels, 4 * 100 * 100));
 }
 
+TEST(DisplayItemList, FilterItem) {
+  gfx::Rect layer_rect(100, 100);
+  FilterOperations filters;
+  unsigned char pixels[4 * 100 * 100] = {0};
+  scoped_refptr<DisplayItemList> list = DisplayItemList::Create();
+
+  SkBitmap source_bitmap;
+  source_bitmap.allocN32Pixels(50, 50);
+  SkCanvas source_canvas(source_bitmap);
+  source_canvas.clear(SkColorSetRGB(128, 128, 128));
+
+  // For most SkImageFilters, the |dst| bounds computed by computeFastBounds are
+  // dependent on the provided |src| bounds. This means, for example, that
+  // translating |src| results in a corresponding translation of |dst|. But this
+  // is not the case for all SkImageFilters; for some of them (e.g.
+  // SkBitmapSource), the computation of |dst| in computeFastBounds doesn't
+  // involve |src| at all. Incorrectly assuming such a relationship (e.g. by
+  // 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());
+
+  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());
+  expected_bitmap.installPixels(info, expected_pixels, info.minRowBytes());
+  SkCanvas expected_canvas(expected_bitmap);
+  expected_canvas.drawRect(RectFToSkRect(filter_bounds), paint);
+
+  EXPECT_EQ(0, memcmp(pixels, expected_pixels, 4 * 100 * 100));
+}
+
 }  // namespace
 }  // namespace cc