Update from https://crrev.com/304121

cc/trees/layer_tree_host_pixeltest_filters.cc

Index: cc/trees/layer_tree_host_pixeltest_filters.cc
diff --git a/cc/trees/layer_tree_host_pixeltest_filters.cc b/cc/trees/layer_tree_host_pixeltest_filters.cc
index 40fa2c3e454b16d18a0ff7686a2a0f10115a6a26..dc8cc4a9a0db89a8038e10d8cf59ca4208f322b2 100644
--- a/cc/trees/layer_tree_host_pixeltest_filters.cc
+++ b/cc/trees/layer_tree_host_pixeltest_filters.cc
@@ -136,8 +136,8 @@ TEST_F(LayerTreeHostFiltersPixelTest, BackgroundFilterBlurOffAxis) {
   blur->SetBackgroundFilters(filters);
 
 #if defined(OS_WIN)
-  // Windows has 153 pixels off by at most 2: crbug.com/225027
-  float percentage_pixels_large_error = 0.3825f;  // 153px / (200*200)
+  // Windows has 116 pixels off by at most 2: crbug.com/225027
+  float percentage_pixels_large_error = 0.3f;  // 116px / (200*200), rounded up
   float percentage_pixels_small_error = 0.0f;
   float average_error_allowed_in_bad_pixels = 1.f;
   int large_error_allowed = 2;
@@ -277,6 +277,63 @@ TEST_F(ImageFilterClippedPixelTest, ImageFilterClipped_Software) {
   RunPixelTestType(PIXEL_TEST_SOFTWARE);
 }
 
+TEST_F(LayerTreeHostFiltersPixelTest, ImageFilterScaled_GL) {
+  scoped_refptr<SolidColorLayer> background =
+      CreateSolidColorLayer(gfx::Rect(200, 200), SK_ColorWHITE);
+
+  gfx::Rect rect(50, 50, 100, 100);
+
+  static const int kInset = 3;
+  for (int i = 0; !rect.IsEmpty(); ++i) {
+    scoped_refptr<SolidColorLayer> layer =
+        CreateSolidColorLayer(rect, (i & 1) ? SK_ColorWHITE : SK_ColorRED);
+
+    gfx::Transform transform;
+    transform.Translate(rect.width() / 2.0, rect.height() / 2.0);
+    transform.RotateAboutZAxis(30.0);
+    transform.Translate(-rect.width() / 2.0, -rect.height() / 2.0);
+    layer->SetTransform(transform);
+
+    background->AddChild(layer);
+
+    rect.Inset(kInset, kInset);
+  }
+
+  scoped_refptr<SolidColorLayer> filter =
+      CreateSolidColorLayer(gfx::Rect(100, 0, 100, 200), SK_ColorTRANSPARENT);
+
+  background->AddChild(filter);
+
+  // Apply a scale to |background| so that we can see any scaling artifacts that
+  // may appear.
+  gfx::Transform background_transform;
+  static float scale = 1.1f;
+  background_transform.Scale(scale, scale);
+  background->SetTransform(background_transform);
+
+  FilterOperations filters;
+  filters.Append(FilterOperation::CreateGrayscaleFilter(1.0f));
+  filter->SetBackgroundFilters(filters);
+
+#if defined(OS_WIN)
+  // Windows has 153 pixels off by at most 2: crbug.com/225027
+  float percentage_pixels_large_error = 0.3825f;  // 153px / (200*200)
+  float percentage_pixels_small_error = 0.0f;
+  float average_error_allowed_in_bad_pixels = 1.f;
+  int large_error_allowed = 2;
+  int small_error_allowed = 0;
+  pixel_comparator_.reset(new FuzzyPixelComparator(
+      true,  // discard_alpha
+      percentage_pixels_large_error, percentage_pixels_small_error,
+      average_error_allowed_in_bad_pixels, large_error_allowed,
+      small_error_allowed));
+#endif
+
+  // TODO(hendrikw): Enable test in software as well: crbug.com/432157
+  RunPixelTest(PIXEL_TEST_GL, background,
+               base::FilePath(FILE_PATH_LITERAL("filter_on_scaled_layer.png")));
+}
+
 }  // namespace
 }  // namespace cc