Update from https://crrev.com/304121

cc/trees/layer_tree_host_common.cc

Index: cc/trees/layer_tree_host_common.cc
diff --git a/cc/trees/layer_tree_host_common.cc b/cc/trees/layer_tree_host_common.cc
index fd15b52998962b624e1b65f06b4c42aba4a9b0fb..0ff66084cc76ad08a064d933edc6058dde880d18 100644
--- a/cc/trees/layer_tree_host_common.cc
+++ b/cc/trees/layer_tree_host_common.cc
@@ -1883,6 +1883,7 @@ static void CalculateDrawPropertiesInternal(
     render_surface->SetDrawOpacityIsAnimating(animating_opacity_to_target);
     animating_opacity_to_target = false;
     layer_draw_properties.opacity = 1.f;
+    layer_draw_properties.blend_mode = SkXfermode::kSrcOver_Mode;
     layer_draw_properties.opacity_is_animating = animating_opacity_to_target;
     layer_draw_properties.screen_space_opacity_is_animating =
         animating_opacity_to_screen;
@@ -2007,6 +2008,7 @@ static void CalculateDrawPropertiesInternal(
     layer_draw_properties.screen_space_transform_is_animating =
         animating_transform_to_screen;
     layer_draw_properties.opacity = accumulated_draw_opacity;
+    layer_draw_properties.blend_mode = layer->blend_mode();
     layer_draw_properties.opacity_is_animating = animating_opacity_to_target;
     layer_draw_properties.screen_space_opacity_is_animating =
         animating_opacity_to_screen;