Apply skew on both axes together rather than sequentially on Compositor

thread.

Currently skew is not implemented correctly on the Compositor thread.
Instead of calling skew(angle_x, angle_y), the implementation calls
skewX(angle_x) followed by skewY(angle_y). This leads to a different
result. This patch applied skew on both axes together rather than
calling skewX(angle_x) and skewX(angle_Y) sequentially. FF and IE
correctly call skew(angle_x, angle_y).

BUG=268468

Review URL: https://codereview.chromium.org/1325803002

Cr-Commit-Position: refs/heads/master@{#347089}

3 files changed, 8 insertions, 14 deletions

diff --git a/cc/animation/transform_operation.cc b/cc/animation/transform_operation.cc
index 7421924..465429d 100644
--- a/cc/animation/transform_operation.cc
+++ b/cc/animation/transform_operation.cc
@@ -157,8 +157,8 @@ bool TransformOperation::BlendTransformOperations(
     SkMScalar from_y = IsOperationIdentity(from) ? 0 : from->skew.y;
     SkMScalar to_x = IsOperationIdentity(to) ? 0 : to->skew.x;
     SkMScalar to_y = IsOperationIdentity(to) ? 0 : to->skew.y;
-    result->SkewX(BlendSkMScalars(from_x, to_x, progress));
-    result->SkewY(BlendSkMScalars(from_y, to_y, progress));
+    result->Skew(BlendSkMScalars(from_x, to_x, progress),
+                 BlendSkMScalars(from_y, to_y, progress));
     break;
   }
   case TransformOperation::TRANSFORM_OPERATION_PERSPECTIVE: {
diff --git a/cc/animation/transform_operations.cc b/cc/animation/transform_operations.cc
index fb1c17d..29a3d90 100644
--- a/cc/animation/transform_operations.cc
+++ b/cc/animation/transform_operations.cc
@@ -224,8 +224,7 @@ void TransformOperations::AppendScale(SkMScalar x, SkMScalar y, SkMScalar z) {
 
 void TransformOperations::AppendSkew(SkMScalar x, SkMScalar y) {
   TransformOperation to_add;
-  to_add.matrix.SkewX(x);
-  to_add.matrix.SkewY(y);
+  to_add.matrix.Skew(x, y);
   to_add.type = TransformOperation::TRANSFORM_OPERATION_SKEW;
   to_add.skew.x = x;
   to_add.skew.y = y;
diff --git a/cc/animation/transform_operations_unittest.cc b/cc/animation/transform_operations_unittest.cc
index c5fb3c6..5a195227 100644
--- a/cc/animation/transform_operations_unittest.cc
+++ b/cc/animation/transform_operations_unittest.cc
@@ -209,8 +209,7 @@ TEST(TransformOperationTest, ApplySkew) {
   TransformOperations operations;
   operations.AppendSkew(x, y);
   gfx::Transform expected;
-  expected.SkewX(x);
-  expected.SkewY(y);
+  expected.Skew(x, y);
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected, operations.Apply());
 }
 
@@ -552,8 +551,7 @@ TEST(TransformOperationTest, BlendSkewFromEmpty) {
   SkMScalar progress = 0.5f;
 
   gfx::Transform expected;
-  expected.SkewX(1);
-  expected.SkewY(1);
+  expected.Skew(1, 1);
 
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected,
                                   operations.Blend(empty_operation, progress));
@@ -561,8 +559,7 @@ TEST(TransformOperationTest, BlendSkewFromEmpty) {
   progress = -0.5f;
 
   expected.MakeIdentity();
-  expected.SkewX(-1);
-  expected.SkewY(-1);
+  expected.Skew(-1, -1);
 
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected,
                                   operations.Blend(empty_operation, progress));
@@ -570,8 +567,7 @@ TEST(TransformOperationTest, BlendSkewFromEmpty) {
   progress = 1.5f;
 
   expected.MakeIdentity();
-  expected.SkewX(3);
-  expected.SkewY(3);
+  expected.Skew(3, 3);
 
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected,
                                   operations.Blend(empty_operation, progress));
@@ -658,8 +654,7 @@ TEST(TransformOperationTest, BlendSkewToEmpty) {
   SkMScalar progress = 0.5f;
 
   gfx::Transform expected;
-  expected.SkewX(1);
-  expected.SkewY(1);
+  expected.Skew(1, 1);
 
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected,
                                   empty_operation.Blend(operations, progress));