cc: Let skia veto gpu rasterization.

cc/resources/picture_pile.cc

Index: cc/resources/picture_pile.cc
diff --git a/cc/resources/picture_pile.cc b/cc/resources/picture_pile.cc
index 1af8b4ce05a9df51aaf5b6a4ea7da0cb658e9828..33d37e7f6ef71259401a44c7d07cfa4397c9f76d 100644
--- a/cc/resources/picture_pile.cc
+++ b/cc/resources/picture_pile.cc
@@ -141,8 +141,7 @@ float ClusterTiles(const std::vector<gfx::Rect>& invalid_tiles,
 
 namespace cc {
 
-PicturePile::PicturePile() {
-}
+PicturePile::PicturePile() : is_suitable_for_gpu_rasterization_(true) {}
 
 PicturePile::~PicturePile() {
 }
@@ -244,6 +243,14 @@ bool PicturePile::Update(ContentLayerClient* painter,
                                   tile_grid_info_,
                                   gather_pixel_refs,
                                   num_raster_threads);
+        // Note the '&&' with previous is-suitable state.
+        // This means that once a picture-pile becomes unsuitable for gpu
+        // rasterization due to some content, it will continue to be unsuitable
+        // even if that content is replaced by gpu-friendly content.
+        // This is an optimization to avoid iterating though all pictures in
+        // the pile after each invalidation.
+        is_suitable_for_gpu_rasterization_ &=
+            picture->IsSuitableForGpuRasterization();
         base::TimeDelta duration =
             stats_instrumentation->EndRecording(start_time);
         best_duration = std::min(duration, best_duration);