cc: Update pending tree when external constraints change

External tile constraint updates should update draw
properties in pending tree. Otherwise it's possible that
pending tree remains out of sync even after activation.

Not the external draw properties do not need to be updated
since activation does not by itself update active tree draw
properties.

BUG=552398
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1672453002

Cr-Commit-Position: refs/heads/master@{#374194}

1 files changed, 34 insertions, 0 deletions

diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index fe913c3..600047c 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -9009,6 +9009,40 @@ TEST_F(ResourcelessSoftwareLayerTreeHostImplTest,
   EXPECT_FALSE(did_request_prepare_tiles_);
 }
 
+TEST_F(LayerTreeHostImplTest, ExternalTileConstraintReflectedInPendingTree) {
+  EXPECT_FALSE(host_impl_->CommitToActiveTree());
+  const gfx::Size layer_size(100, 100);
+  host_impl_->SetViewportSize(layer_size);
+  bool update_lcd_text = false;
+
+  // Set up active and pending tree.
+  host_impl_->CreatePendingTree();
+  host_impl_->pending_tree()->SetRootLayer(
+      LayerImpl::Create(host_impl_->pending_tree(), 1));
+  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
+  host_impl_->pending_tree()->UpdateDrawProperties(update_lcd_text);
+
+  host_impl_->ActivateSyncTree();
+  host_impl_->active_tree()->BuildPropertyTreesForTesting();
+  host_impl_->active_tree()->UpdateDrawProperties(update_lcd_text);
+
+  host_impl_->CreatePendingTree();
+  host_impl_->pending_tree()->UpdateDrawProperties(update_lcd_text);
+  host_impl_->active_tree()->UpdateDrawProperties(update_lcd_text);
+
+  EXPECT_FALSE(host_impl_->pending_tree()->needs_update_draw_properties());
+  EXPECT_FALSE(host_impl_->active_tree()->needs_update_draw_properties());
+
+  // Update external constraints should set_needs_update_draw_properties on
+  // both trees.
+  gfx::Transform external_transform;
+  gfx::Rect external_viewport(10, 20);
+  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
+                                                 external_transform);
+  EXPECT_TRUE(host_impl_->pending_tree()->needs_update_draw_properties());
+  EXPECT_TRUE(host_impl_->active_tree()->needs_update_draw_properties());
+}
+
 TEST_F(LayerTreeHostImplTest, ExternalViewportAffectsVisibleRects) {
   const gfx::Size layer_size(100, 100);
   SetupScrollAndContentsLayers(layer_size);