cc: Use ScreenSpaceTransform to determine content scale

cc/trees/layer_tree_host_common_unittest.cc

 // Copyright 2011 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/trees/layer_tree_host_common.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 4607 matching lines @@
   gfx::Transform perspective_matrix;
   perspective_matrix.ApplyPerspectiveDepth(2.0);
 
   gfx::Transform scale_small_matrix;
   scale_small_matrix.Scale(SK_MScalar1 / 10.f, SK_MScalar1 / 12.f);
 
   LayerImpl* root = root_layer();
   SetLayerPropertiesForTesting(root, identity_matrix, gfx::Point3F(),
                                gfx::PointF(), gfx::Size(100, 100), false, true,
                                false);
-  LayerImpl* parent = AddChildToRoot<LayerImpl>();
+
+  LayerImpl* page_scale = AddChildToRoot<LayerImpl>();
+  SetLayerPropertiesForTesting(page_scale, identity_matrix, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(100, 100), false, true,
+                               false);
+
+  LayerImpl* parent = AddChild<LayerImpl>(page_scale);
   parent->SetDrawsContent(true);
   SetLayerPropertiesForTesting(parent, identity_matrix, gfx::Point3F(),
                                gfx::PointF(), gfx::Size(100, 100), false, true,
                                false);
 
   LayerImpl* perspective_surface = AddChild<LayerImpl>(parent);
   SetLayerPropertiesForTesting(perspective_surface,
                                perspective_matrix * scale_small_matrix,
                                gfx::Point3F(), gfx::PointF(2.f, 2.f),
                                gfx::Size(10, 10), false, true, true);
   perspective_surface->SetDrawsContent(true);
 
   LayerImpl* scale_surface = AddChild<LayerImpl>(parent);
   SetLayerPropertiesForTesting(scale_surface, scale_small_matrix,
                                gfx::Point3F(), gfx::PointF(2.f, 2.f),
                                gfx::Size(10, 10), false, true, true);
   scale_surface->SetDrawsContent(true);
 
   float device_scale_factor = 2.5f;
   float page_scale_factor = 3.f;
+  root->layer_tree_impl()->SetViewportLayersFromIds(
+      Layer::INVALID_ID, page_scale->id(), Layer::INVALID_ID,
+      Layer::INVALID_ID);
+  root->layer_tree_impl()->SetDeviceScaleFactor(device_scale_factor);
+  root->layer_tree_impl()->BuildPropertyTreesForTesting();
+  root->layer_tree_impl()->SetPageScaleOnActiveTree(page_scale_factor);
   ExecuteCalculateDrawProperties(root, device_scale_factor, page_scale_factor,
                                  root);
 
   EXPECT_IDEAL_SCALE_EQ(device_scale_factor * page_scale_factor, parent);
   EXPECT_IDEAL_SCALE_EQ(device_scale_factor * page_scale_factor,
                         perspective_surface);
   // Ideal scale is the max 2d scale component of the combined transform up to
   // the nearest render target. Here this includes the layer transform as well
   // as the device and page scale factors.
   gfx::Transform transform = scale_small_matrix;
@@ skipping 5429 matching lines @@
   EXPECT_EQ(scroll_child6.id, grand_child10->scroll_tree_index());
   EXPECT_EQ(scroll_root1.id, parent3->scroll_tree_index());
   EXPECT_EQ(scroll_child7.id, child8->scroll_tree_index());
   EXPECT_EQ(scroll_root1.id, parent4->scroll_tree_index());
   EXPECT_EQ(scroll_root1.id, child9->scroll_tree_index());
   EXPECT_EQ(scroll_root1.id, grand_child12->scroll_tree_index());
 }
 
 }  // namespace
 }  // namespace cc