Match html canvas which is transferred to OffscreenCanvas to CSS style

cc/layers/surface_layer_impl_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/layers/surface_layer_impl.h"
 
 #include <stddef.h>
 
+#include "cc/layers/append_quads_data.h"
 #include "cc/test/layer_test_common.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
 namespace {
 
 static constexpr FrameSinkId kArbitraryFrameSinkId(1, 1);
 
 TEST(SurfaceLayerImplTest, Occlusion) {
   gfx::Size layer_size(1000, 1000);
@@ skipping 40 matching lines @@
 
     size_t partially_occluded_count = 0;
     LayerTestCommon::VerifyQuadsAreOccluded(
         impl.quad_list(), occluded, &partially_occluded_count);
     // The layer outputs one quad, which is partially occluded.
     EXPECT_EQ(1u, impl.quad_list().size());
     EXPECT_EQ(1u, partially_occluded_count);
   }
 }
 
+TEST(SurfaceLayerImplTest, LayerBoundsDiffFromSurfaceLayerSize) {
+  LayerTestCommon::LayerImplTest impl;
+  SurfaceLayerImpl* surface_layer_impl =
+      impl.AddChildToRoot<SurfaceLayerImpl>();
+  const LocalFrameId kArbitraryLocalFrameId(9,
+                                            base::UnguessableToken::Create());
+
+  gfx::Size layer_size(100, 300);
+  gfx::Size surface_size(350, 350);
+  float surface_scale = 2.f;
+  surface_layer_impl->SetBounds(layer_size);
+  surface_layer_impl->SetDrawsContent(true);
+  SurfaceId surface_id(kArbitraryFrameSinkId, kArbitraryLocalFrameId);
+  surface_layer_impl->SetSurfaceId(surface_id);
+  surface_layer_impl->SetSurfaceScale(surface_scale);
+  surface_layer_impl->SetSurfaceSize(surface_size);
+
+  std::unique_ptr<RenderPass> render_pass = RenderPass::Create();
+  AppendQuadsData data;
+  surface_layer_impl->AppendQuads(render_pass.get(), &data);
+
+  const QuadList& quads = render_pass->quad_list;
+  ASSERT_EQ(1u, quads.size());
+  EXPECT_EQ(DrawQuad::SURFACE_CONTENT, quads.front()->material);
+  const SharedQuadState* shared_quad_state = quads.front()->shared_quad_state;
+
+  gfx::Transform transform;
+  float scale_x = 350.f / 100.f;
+  float scale_y = 350.f / 300.f;
+  transform.Scale(SK_MScalar1 / scale_x, SK_MScalar1 / scale_y);
+  EXPECT_EQ(transform, shared_quad_state->quad_to_target_transform);
+}
+
 }  // namespace
 }  // namespace cc