Animation start scale should be considered for the raster scale

cc/layers/draw_properties.h

Index: cc/layers/draw_properties.h
diff --git a/cc/layers/draw_properties.h b/cc/layers/draw_properties.h
index 930f7bf0e95a29119937d0ad85adff2193f2959e..3dfb203b33b116c679c50efe676bb095e0da2e4a 100644
--- a/cc/layers/draw_properties.h
+++ b/cc/layers/draw_properties.h
@@ -43,6 +43,7 @@ struct CC_EXPORT DrawProperties {
         last_drawn_render_surface_layer_list_id(0),
         ideal_contents_scale(0.f),
         maximum_animation_contents_scale(0.f),
+        starting_animation_contents_scale(0.f),
         page_scale_factor(0.f),
         device_scale_factor(0.f) {}
 
@@ -156,6 +157,10 @@ struct CC_EXPORT DrawProperties {
   // should be rastered at to be crisp.
   float maximum_animation_contents_scale;
 
+  // The scale during the layer animation start at which content should be
+  // rastered at to be crisp.
+  float starting_animation_contents_scale;
+
   // The page scale factor that is applied to the layer. Since some layers may
   // have page scale applied and others not, this may differ between layers.
   float page_scale_factor;