cc: Invalidate newly recycled tilings upon swapping.

This patch changes the way we invalidate recycled tiles. Previously,
we would keep unshared tiles on the recycle tree until we create a new
pending tree. When we do that, we invalidate two frames worth of
invalidation. However, this relies on the tile manager to release
memory from these tiles and doesn't yield itself to changes.

The new approach invalidates the current invalidation on the recycle
tree as soon as the tilings are swapped, which ensures that in that
frame the tiles that are not shared are already released.

R=enne

Review URL: https://codereview.chromium.org/227673013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262670 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 16 insertions, 4 deletions

diff --git a/cc/resources/picture_layer_tiling.cc b/cc/resources/picture_layer_tiling.cc
index 95f9546..5fa9d05 100644
--- a/cc/resources/picture_layer_tiling.cc
+++ b/cc/resources/picture_layer_tiling.cc
@@ -179,7 +179,16 @@ void PictureLayerTiling::SetLayerBounds(const gfx::Size& layer_bounds) {
   Invalidate(layer_region);
 }
 
+void PictureLayerTiling::RemoveTilesInRegion(const Region& layer_region) {
+  DoInvalidate(layer_region, false /* recreate_tiles */);
+}
+
 void PictureLayerTiling::Invalidate(const Region& layer_region) {
+  DoInvalidate(layer_region, true /* recreate_tiles */);
+}
+
+void PictureLayerTiling::DoInvalidate(const Region& layer_region,
+                                      bool recreate_tiles) {
   std::vector<TileMapKey> new_tile_keys;
   for (Region::Iterator iter(layer_region); iter.has_rect(); iter.next()) {
     gfx::Rect layer_rect = iter.rect();
@@ -198,13 +207,16 @@ void PictureLayerTiling::Invalidate(const Region& layer_region) {
       if (find == tiles_.end())
         continue;
       tiles_.erase(find);
-      new_tile_keys.push_back(key);
+      if (recreate_tiles)
+        new_tile_keys.push_back(key);
     }
   }
 
-  const PictureLayerTiling* twin_tiling = client_->GetTwinTiling(this);
-  for (size_t i = 0; i < new_tile_keys.size(); ++i)
-    CreateTile(new_tile_keys[i].first, new_tile_keys[i].second, twin_tiling);
+  if (recreate_tiles) {
+    const PictureLayerTiling* twin_tiling = client_->GetTwinTiling(this);
+    for (size_t i = 0; i < new_tile_keys.size(); ++i)
+      CreateTile(new_tile_keys[i].first, new_tile_keys[i].second, twin_tiling);
+  }
 }
 
 PictureLayerTiling::CoverageIterator::CoverageIterator()