cc: ReadyToDraw notifications.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index c3c7ca021104ba5f2468b233838d45beee16c845..aaf3481ffa7b66449fae4362768f13699a794799 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -1405,12 +1405,9 @@ bool PictureLayerImpl::HasValidTilePriorities() const {
   return IsOnActiveOrPendingTree() && IsDrawnRenderSurfaceLayerListMember();
 }
 
-bool PictureLayerImpl::AllTilesRequiredForActivationAreReadyToDraw() const {
-  TRACE_EVENT0("cc",
-               "PictureLayerImpl::AllTilesRequiredForActivationAreReadyToDraw");
-  if (!layer_tree_impl()->IsPendingTree())
-    return true;
-
+template <typename F>

[vmpstr, 2014/11/03 23:07:00]

nit: I think F == bool (*)(PictureLayerTiling*, const Tile*) in both cases where
this is used, but feel free to leave it as in, I guess.

For bonus points (or extra complexity :P), we can

typedef bool(PictureLayerTiling::*TileRequirementCheck)(const Tile*); 
then take const TileRequirementCheck& is_tile_required (or keep template
<typename F> instead of these two steps),

and pass &PictureLayerTiling::IsTileRequiredForActivationIfVisible or
&PictureLayerTiling::IsTileRequiredForDrawIfVisible, then do

if ((tiling->*is_tile_required_callback)(tile) && !tile->IsReadyToDraw)

thus eliminating the need for the two functions.

*runs to hide* This is probably too complicated, so feel free to ignore all of
it. We could use a lambda here but I don't think those are allowed yet?

[ernstm, 2014/11/04 00:21:55]

Done. This is what I originally wanted to do, but I didn't know about operator
->*. Thanks!

I've dropped the const reference to function pointer and pass the function
pointer by value instead. Does the const reference offer any benefits in this
situation?

+bool PictureLayerImpl::AllTilesRequiredAreReadyToDraw(
+    const F& is_tile_required_callback) const {
   if (!HasValidTilePriorities())
     return true;
 
@@ -1442,11 +1439,8 @@ bool PictureLayerImpl::AllTilesRequiredForActivationAreReadyToDraw() const {
       // be out of date. It is updated in the raster/eviction iterators.
       // TODO(vmpstr): Remove the comment once you can't access this information
       // from the tile.
-      if (tiling->IsTileRequiredForActivation(tile) && !tile->IsReadyToDraw()) {
-        TRACE_EVENT_INSTANT0("cc",
-                             "PictureLayerImpl::"
-                             "AllTilesRequiredForActivationAreReadyToDraw not "
-                             "ready to activate",
+      if (is_tile_required_callback(tiling, tile) && !tile->IsReadyToDraw()) {
+        TRACE_EVENT_INSTANT0("cc", "Tile required, but not ready to draw.",
                              TRACE_EVENT_SCOPE_THREAD);
         return false;
       }
@@ -1456,6 +1450,37 @@ bool PictureLayerImpl::AllTilesRequiredForActivationAreReadyToDraw() const {
   return true;
 }
 
+namespace {

[vmpstr, 2014/11/03 23:07:00]

nit: I prefer anonymous namespace to be at the top of the file (there is already
a namespace there, I think, it's just a matter of putting these in there). 

[ernstm, 2014/11/04 00:21:55]

Done.

+bool IsTileRequiredForActivationIfVisible(PictureLayerTiling* tiling,
+                                          const Tile* tile) {
+  return tiling->IsTileRequiredForActivationIfVisible(tile);
+}
+
+bool IsTileRequiredForDrawIfVisible(PictureLayerTiling* tiling,
+                                    const Tile* tile) {
+  return tiling->IsTileRequiredForDrawIfVisible(tile);
+}
+}  // namespace
+
+bool PictureLayerImpl::AllTilesRequiredForActivationAreReadyToDraw() const {
+  TRACE_EVENT0("cc",
+               "PictureLayerImpl::AllTilesRequiredForActivationAreReadyToDraw");
+
+  if (!layer_tree_impl()->IsPendingTree())
+    return true;
+
+  return AllTilesRequiredAreReadyToDraw(&IsTileRequiredForActivationIfVisible);
+}
+
+bool PictureLayerImpl::AllTilesRequiredForDrawAreReadyToDraw() const {
+  TRACE_EVENT0("cc", "PictureLayerImpl::AllTilesRequiredForDrawAreReadyToDraw");
+
+  if (!layer_tree_impl()->IsActiveTree())
+    return true;
+
+  return AllTilesRequiredAreReadyToDraw(&IsTileRequiredForDrawIfVisible);
+}
+
 PictureLayerImpl::LayerRasterTileIterator::LayerRasterTileIterator()
     : layer_(nullptr), current_stage_(arraysize(stages_)) {
 }