cc: Implement and use FilterOperations::MapRectReverse for mapping backdrop bounding box.

cc/output/filter_operations_unittest.cc

 // Copyright 2013 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 <stddef.h>
 
 #include "cc/output/filter_operations.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/effects/SkBlurImageFilter.h"
 #include "third_party/skia/include/effects/SkDropShadowImageFilter.h"
@@ skipping 16 matching lines @@
   EXPECT_EQ(60, left);
 }
 
 TEST(FilterOperationsTest, MapRectBlur) {
   FilterOperations ops;
   ops.Append(FilterOperation::CreateBlurFilter(20));
   EXPECT_EQ(gfx::Rect(-60, -60, 130, 130),
             ops.MapRect(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
 }
 
+TEST(FilterOperationsTest, MapRectReverseBlur) {
+  FilterOperations ops;
+  ops.Append(FilterOperation::CreateBlurFilter(20));
+  EXPECT_EQ(gfx::Rect(-60, -60, 130, 130),
+            ops.MapRectReverse(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
+}
+
 TEST(FilterOperationsTest, GetOutsetsDropShadowReferenceFilter) {
   // TODO(hendrikw): We need to make outsets for reference filters be in line
   // with non-reference filters. See crbug.com/523534
   FilterOperations ops;
   ops.Append(
       FilterOperation::CreateReferenceFilter(SkDropShadowImageFilter::Make(
           SkIntToScalar(3), SkIntToScalar(8), SkIntToScalar(4),
           SkIntToScalar(9), SK_ColorBLACK,
           SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode,
           nullptr)));
@@ skipping 12 matching lines @@
   ops.Append(
       FilterOperation::CreateReferenceFilter(SkDropShadowImageFilter::Make(
           SkIntToScalar(3), SkIntToScalar(8), SkIntToScalar(4),
           SkIntToScalar(9), SK_ColorBLACK,
           SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode,
           nullptr)));
   EXPECT_EQ(gfx::Rect(-9, -19, 34, 64),
             ops.MapRect(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
 }
 
+TEST(FilterOperationsTest, MapRectReverseDropShadowReferenceFilter) {
+  FilterOperations ops;
+  ops.Append(
+      FilterOperation::CreateReferenceFilter(SkDropShadowImageFilter::Make(
+          SkIntToScalar(3), SkIntToScalar(8), SkIntToScalar(4),
+          SkIntToScalar(9), SK_ColorBLACK,
+          SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode,
+          nullptr)));
+  EXPECT_EQ(gfx::Rect(-15, -35, 34, 64),
+            ops.MapRectReverse(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
+}
+
 TEST(FilterOperationsTest, MapRectOffsetReferenceFilter) {
   sk_sp<SkImageFilter> filter = SkOffsetImageFilter::Make(30, 40, nullptr);
   FilterOperations ops;
   ops.Append(FilterOperation::CreateReferenceFilter(std::move(filter)));
   EXPECT_EQ(gfx::Rect(30, 40, 10, 10),
             ops.MapRect(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
 }
 
+TEST(FilterOperationsTest, MapRectReverseOffsetReferenceFilter) {
+  sk_sp<SkImageFilter> filter = SkOffsetImageFilter::Make(30, 40, nullptr);
+  FilterOperations ops;
+  ops.Append(FilterOperation::CreateReferenceFilter(std::move(filter)));
+  EXPECT_EQ(gfx::Rect(-30, -40, 10, 10),
+            ops.MapRectReverse(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
+}
+
+TEST(FilterOperationsTest, MapRectCombineNonCommutative) {
+  // Offsets by 100px in each axis, then scales the resulting image by 2.
+  FilterOperations ops;
+  ops.Append(FilterOperation::CreateReferenceFilter(
+      SkOffsetImageFilter::Make(100, 100, nullptr)));
+  SkMatrix scaleMatrix;
+  scaleMatrix.setScale(2, 2);
+  ops.Append(
+      FilterOperation::CreateReferenceFilter(SkImageFilter::MakeMatrixFilter(
+          scaleMatrix, kNone_SkFilterQuality, nullptr)));
+
+  EXPECT_EQ(gfx::Rect(200, 200, 20, 20),
+            ops.MapRect(gfx::Rect(10, 10), SkMatrix::I()));
+}
+
+TEST(FilterOperationsTest, MapRectReverseCombineNonCommutative) {
+  // Offsets by 100px in each axis, then scales the resulting image by 2.
+  FilterOperations ops;
+  ops.Append(FilterOperation::CreateReferenceFilter(
+      SkOffsetImageFilter::Make(100, 100, nullptr)));
+  SkMatrix scaleMatrix;
+  scaleMatrix.setScale(2, 2);
+  ops.Append(
+      FilterOperation::CreateReferenceFilter(SkImageFilter::MakeMatrixFilter(
+          scaleMatrix, kNone_SkFilterQuality, nullptr)));
+
+  EXPECT_EQ(gfx::Rect(10, 10),
+            ops.MapRectReverse(gfx::Rect(200, 200, 20, 20), SkMatrix::I()));
+}
+
 TEST(FilterOperationsTest, GetOutsetsNullReferenceFilter) {
   FilterOperations ops;
   ops.Append(FilterOperation::CreateReferenceFilter(nullptr));
 
   int top, right, bottom, left;
   top = right = bottom = left = 0;
   ops.GetOutsets(&top, &right, &bottom, &left);
   EXPECT_EQ(0, top);
   EXPECT_EQ(0, right);
   EXPECT_EQ(0, bottom);
   EXPECT_EQ(0, left);
 }
 
 TEST(FilterOperationsTest, MapRectNullReferenceFilter) {
   FilterOperations ops;
   ops.Append(FilterOperation::CreateReferenceFilter(nullptr));
   EXPECT_EQ(gfx::Rect(0, 0, 10, 10),
             ops.MapRect(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
 }
 
+TEST(FilterOperationsTest, MapRectReverseNullReferenceFilter) {
+  FilterOperations ops;
+  ops.Append(FilterOperation::CreateReferenceFilter(nullptr));
+  EXPECT_EQ(gfx::Rect(0, 0, 10, 10),
+            ops.MapRectReverse(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
+}
+
 TEST(FilterOperationsTest, GetOutsetsDropShadow) {
   FilterOperations ops;
   ops.Append(FilterOperation::CreateDropShadowFilter(gfx::Point(3, 8), 20, 0));
   int top, right, bottom, left;
   top = right = bottom = left = 0;
   ops.GetOutsets(&top, &right, &bottom, &left);
   EXPECT_EQ(52, top);
   EXPECT_EQ(63, right);
   EXPECT_EQ(68, bottom);
   EXPECT_EQ(57, left);
 }
 
 TEST(FilterOperationsTest, MapRectDropShadow) {
   FilterOperations ops;
   ops.Append(FilterOperation::CreateDropShadowFilter(gfx::Point(3, 8), 20, 0));
   EXPECT_EQ(gfx::Rect(-57, -52, 130, 130),
             ops.MapRect(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
 }
 
+TEST(FilterOperationsTest, MapRectReverseDropShadow) {
+  FilterOperations ops;
+  ops.Append(FilterOperation::CreateDropShadowFilter(gfx::Point(3, 8), 20, 0));
+  EXPECT_EQ(gfx::Rect(-63, -68, 130, 130),
+            ops.MapRectReverse(gfx::Rect(0, 0, 10, 10), SkMatrix::I()));
+}
+
 #define SAVE_RESTORE_AMOUNT(filter_name, filter_type, a)                  \
   {                                                                       \
     FilterOperation op = FilterOperation::Create##filter_name##Filter(a); \
     EXPECT_EQ(FilterOperation::filter_type, op.type());                   \
     EXPECT_EQ(a, op.amount());                                            \
                                                                           \
     FilterOperation op2 = FilterOperation::CreateEmptyFilter();           \
     op2.set_type(FilterOperation::filter_type);                           \
                                                                           \
     EXPECT_NE(a, op2.amount());                                           \
@@ skipping 645 matching lines @@
   blended = to.Blend(from, -0.75);
   EXPECT_EQ(to, blended);
   blended = to.Blend(from, 0.75);
   EXPECT_EQ(to, blended);
   blended = to.Blend(from, 1.5);
   EXPECT_EQ(to, blended);
 }
 
 }  // namespace
 }  // namespace cc