cc: Stop pushing properties every activation for picture layers.

cc/resources/picture_layer_tiling_set.cc

Index: cc/resources/picture_layer_tiling_set.cc
diff --git a/cc/resources/picture_layer_tiling_set.cc b/cc/resources/picture_layer_tiling_set.cc
index 779e2c08e9e6d994b9f4f7e9c25635c42efc8662..bae9df9ff21c0353441040355518767af50e755d 100644
--- a/cc/resources/picture_layer_tiling_set.cc
+++ b/cc/resources/picture_layer_tiling_set.cc
@@ -62,6 +62,8 @@ void PictureLayerTilingSet::UpdateTilingsToCurrentRasterSource(
   RemoveTilingsBelowScale(minimum_contents_scale);
   RemoveTilingsAboveScale(maximum_contents_scale);
 
+  bool added_tiling = false;
+
   // Copy over tilings that are shared with the |twin_set| tiling set (if it
   // exists).
   if (twin_set) {
@@ -78,6 +80,7 @@ void PictureLayerTilingSet::UpdateTilingsToCurrentRasterSource(
             skewport_extrapolation_limit_in_content_pixels_);
         tilings_.push_back(new_tiling.Pass());
         this_tiling = tilings_.back();
+        added_tiling = true;
       }
       this_tiling->CloneTilesAndPropertiesFrom(*twin_tiling);
     }
@@ -127,6 +130,9 @@ void PictureLayerTilingSet::UpdateTilingsToCurrentRasterSource(
       DCHECK_EQ(1u, num_high_res);
   }
 #endif
+
+  if (added_tiling)
+    client_->TilingSetChanged();
 }
 
 void PictureLayerTilingSet::CleanUpTilings(
@@ -187,7 +193,10 @@ void PictureLayerTilingSet::RemoveNonIdealTilings() {
   auto to_remove = tilings_.remove_if([](PictureLayerTiling* t) {
     return t->resolution() == NON_IDEAL_RESOLUTION;
   });
+  bool removed_anything = to_remove != tilings_.end();
   tilings_.erase(to_remove, tilings_.end());
+  if (removed_anything)
+    client_->TilingSetChanged();
 }
 
 void PictureLayerTilingSet::MarkAllTilingsNonIdeal() {
@@ -208,8 +217,9 @@ PictureLayerTiling* PictureLayerTilingSet::AddTiling(
       skewport_target_time_in_seconds_,
       skewport_extrapolation_limit_in_content_pixels_));
   PictureLayerTiling* appended = tilings_.back();
-
   tilings_.sort(LargestToSmallestScaleFunctor());
+
+  client_->TilingSetChanged();
   return appended;
 }
 
@@ -247,7 +257,10 @@ void PictureLayerTilingSet::RemoveTilingsBelowScale(float minimum_scale) {
       tilings_.remove_if([minimum_scale](PictureLayerTiling* tiling) {
         return tiling->contents_scale() < minimum_scale;
       });
+  bool removed_anything = to_remove != tilings_.end();
   tilings_.erase(to_remove, tilings_.end());
+  if (removed_anything)
+    client_->TilingSetChanged();
 }
 
 void PictureLayerTilingSet::RemoveTilingsAboveScale(float maximum_scale) {
@@ -255,11 +268,17 @@ void PictureLayerTilingSet::RemoveTilingsAboveScale(float maximum_scale) {
       tilings_.remove_if([maximum_scale](PictureLayerTiling* tiling) {
         return tiling->contents_scale() > maximum_scale;
       });
+  bool removed_anything = to_remove != tilings_.end();
   tilings_.erase(to_remove, tilings_.end());
+  if (removed_anything)
+    client_->TilingSetChanged();
 }
 
 void PictureLayerTilingSet::RemoveAllTilings() {
+  bool removed_anything = !tilings_.empty();
   tilings_.clear();
+  if (removed_anything)
+    client_->TilingSetChanged();
 }
 
 void PictureLayerTilingSet::Remove(PictureLayerTiling* tiling) {
@@ -268,6 +287,7 @@ void PictureLayerTilingSet::Remove(PictureLayerTiling* tiling) {
   if (iter == tilings_.end())
     return;
   tilings_.erase(iter);
+  client_->TilingSetChanged();
 }
 
 void PictureLayerTilingSet::RemoveAllTiles() {