cc: Change required_for_activation bookkeeping.

cc/layers/picture_layer_impl.h

Index: cc/layers/picture_layer_impl.h
diff --git a/cc/layers/picture_layer_impl.h b/cc/layers/picture_layer_impl.h
index cd7c68b32a42bec85d1f868f4d0c1c153e577cf3..f01d835029b93927648db26626e0dec6ff855db4 100644
--- a/cc/layers/picture_layer_impl.h
+++ b/cc/layers/picture_layer_impl.h
@@ -92,6 +92,7 @@ class CC_EXPORT PictureLayerImpl
   virtual void AppendQuads(QuadSink* quad_sink,
                            AppendQuadsData* append_quads_data) OVERRIDE;
   virtual void UpdateTilePriorities() OVERRIDE;
+  virtual void NotifyTileInitialized(const Tile* tile) OVERRIDE;
   virtual void DidBecomeActive() OVERRIDE;
   virtual void DidBeginTracing() OVERRIDE;
   virtual void ReleaseResources() OVERRIDE;
@@ -139,6 +140,14 @@ class CC_EXPORT PictureLayerImpl
   WhichTree GetTree() const;
   bool IsOnActiveOrPendingTree() const;
 
+  // Return the count of tiles on this layer that meet both of the following
+  // conditions:
+  // 1. The tile is required for activation.
+  // 2. The tile needs initialization (ie, it's not ready to draw).
+  size_t UninitializedTilesRequiredForActivationCount() const {
+    return uninitialized_tiles_required_for_activation_count_;
+  }
+
  protected:
   friend class LayerRasterTileIterator;
 
@@ -162,13 +171,13 @@ class CC_EXPORT PictureLayerImpl
   float SnappedContentsScale(float new_contents_scale);
   void UpdateLCDTextStatus(bool new_status);
   void ResetRasterScale();
-  void MarkVisibleResourcesAsRequired() const;
+  void MarkVisibleResourcesAsRequired();
   bool MarkVisibleTilesAsRequired(
       PictureLayerTiling* tiling,
       const PictureLayerTiling* optional_twin_tiling,
       float contents_scale,
       const gfx::Rect& rect,
-      const Region& missing_region) const;
+      const Region& missing_region);
 
   void DoPostCommitInitializationIfNeeded() {
     if (needs_post_commit_initialization_)
@@ -220,6 +229,8 @@ class CC_EXPORT PictureLayerImpl
   gfx::Size viewport_size_for_tile_priority_;
   gfx::Transform screen_space_transform_for_tile_priority_;
 
+  size_t uninitialized_tiles_required_for_activation_count_;

[enne (OOO), 2014/04/29 19:44:19]

Ah, I think I get it, because TileManager has no global pass over all tiles,
then it doesn't know how many tiles are required for activation anymore, and the
layer has to keep track of that.

[vmpstr, 2014/04/29 22:56:20]

Ya, that's exactly right. The plan is to not have this check in AssignGpuMemory
at all, and instead the tile manager will check this before sending activation
signals to check whether it can actually activate. This is just a first step
that makes it possible to not iterate every tile.

+
   friend class PictureLayer;
   DISALLOW_COPY_AND_ASSIGN(PictureLayerImpl);
 };