cc: Make animated opacity trigger render surface creation

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 8464 matching lines @@
   EXPECT_EQ(gfx::Rect(), animated->visible_layer_rect_for_testing());
 
   // This time, flattening does not make |animated|'s transform invertible. This
   // means the clip cannot be projected into |surface|'s space, so we treat
   // |surface| and layers that draw into it as having empty visible rect.
   EXPECT_EQ(gfx::Rect(), surface->visible_layer_rect_for_testing());
   EXPECT_EQ(gfx::Rect(),
             descendant_of_animation->visible_layer_rect_for_testing());
 }
 
+// Verify that having animated opacity but current opacity 1 still creates
+// a render surface.
+TEST_F(LayerTreeHostCommonTest, AnimatedOpacityCreatesRenderSurface) {
+  LayerImpl* root = root_layer_for_testing();
+  LayerImpl* child = AddChild<LayerImpl>(root);
+  LayerImpl* grandchild = AddChild<LayerImpl>(child);
+  child->SetDrawsContent(true);
+  grandchild->SetDrawsContent(true);
+
+  gfx::Transform identity_transform;
+  SetLayerPropertiesForTesting(root, identity_transform, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(50, 50), true, false);
+  SetLayerPropertiesForTesting(child, identity_transform, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(50, 50), true, false);
+  SetLayerPropertiesForTesting(grandchild, identity_transform, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(50, 50), true, false);
+
+  SetElementIdsForTesting();
+  AddOpacityTransitionToElementWithPlayer(child->element_id(), timeline_impl(),
+                                          10.0, 1.f, 0.2f, false);
+  ExecuteCalculateDrawProperties(root);
+
+  EXPECT_EQ(1.f, child->Opacity());
+  EXPECT_TRUE(root->has_render_surface());
+  EXPECT_TRUE(child->has_render_surface());
+  EXPECT_FALSE(grandchild->has_render_surface());
+}
+
 // Verify that having an animated filter (but no current filter, as these
 // are mutually exclusive) correctly creates a render surface.
 TEST_F(LayerTreeHostCommonTest, AnimatedFilterCreatesRenderSurface) {
   LayerImpl* root = root_layer_for_testing();
   LayerImpl* child = AddChild<LayerImpl>(root);
   LayerImpl* grandchild = AddChild<LayerImpl>(child);
 
   gfx::Transform identity_transform;
   SetLayerPropertiesForTesting(root, identity_transform, gfx::Point3F(),
                                gfx::PointF(), gfx::Size(50, 50), true, false);
@@ skipping 2026 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