cc: ReadyToDraw notifications.

cc/resources/picture_layer_tiling.cc

Index: cc/resources/picture_layer_tiling.cc
diff --git a/cc/resources/picture_layer_tiling.cc b/cc/resources/picture_layer_tiling.cc
index f47c700febaf7ee6ff8696be57dd9f2ad9a27672..3a9a1eaeeb3bda0bb7a0a77f3f3ec525ba167488 100644
--- a/cc/resources/picture_layer_tiling.cc
+++ b/cc/resources/picture_layer_tiling.cc
@@ -734,6 +734,25 @@ bool PictureLayerTiling::IsTileRequiredForActivation(const Tile* tile) const {
   return true;
 }
 
+bool PictureLayerTiling::IsTileRequiredForDraw(const Tile* tile) const {
+  DCHECK_EQ(ACTIVE_TREE, client_->GetTree());
+
+  // Note that although this function will determine whether tile is required

[vmpstr, 2014/10/24 18:02:24]

Same here.

[ernstm, 2014/10/27 21:13:56]

Done.

+  // for draw assuming that it is in visible (ie in the viewport). That is
+  // to say, even if the tile is outside of the viewport, it will be treated as
+  // if it was inside (there are no explicit checks for this). Hence, this
+  // function is only called for visible tiles to ensure we don't block
+  // activation on tiles outside of the viewport.

[vmpstr, 2014/10/24 18:02:24]

This is not correct, this should say something similar about draw.

[enne (OOO), 2014/10/24 19:16:28]

"activation", eh?

I know that this is a copy-paste from IsTileRequiredForActivation.  Could these
be renamed to be like IsTileRequiredForFoobarIfVisible to make it clear that
it's not the final determination?  I think that would help not need this
gigantic comment?

[ernstm, 2014/10/27 21:13:56]

Done.

+
+  if (resolution_ != HIGH_RESOLUTION)
+    return false;
+
+  if (IsTileOccluded(tile))
+    return false;
+
+  return true;
+}
+
 void PictureLayerTiling::UpdateTileAndTwinPriority(Tile* tile) const {
   UpdateTilePriority(tile);
 
@@ -745,6 +764,8 @@ void PictureLayerTiling::UpdateTileAndTwinPriority(Tile* tile) const {
     tile->set_is_occluded(twin_tree, false);
     if (twin_tree == PENDING_TREE)
       tile->set_required_for_activation(false);
+    else
+      tile->set_required_for_draw(false);
     return;
   }
 
@@ -765,12 +786,16 @@ void PictureLayerTiling::UpdateTilePriority(Tile* tile) const {
     tile->SetPriority(tree, TilePriority(resolution_, TilePriority::NOW, 0));
     if (tree == PENDING_TREE)
       tile->set_required_for_activation(IsTileRequiredForActivation(tile));
+    else
+      tile->set_required_for_draw(IsTileRequiredForDraw(tile));
     tile->set_is_occluded(tree, IsTileOccluded(tile));
     return;
   }
 
   if (tree == PENDING_TREE)
     tile->set_required_for_activation(false);
+  else
+    tile->set_required_for_draw(false);
   tile->set_is_occluded(tree, false);
 
   DCHECK_GT(content_to_screen_scale_, 0.f);