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 0e2e36310206d2eff158afd53993407dbe3ca342..8a15ea604e71558441fab48c7194740003c61c7a 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() {
 }
@@ -245,6 +244,14 @@ bool PicturePile::Update(ContentLayerClient* painter,
                                   gather_pixel_refs,
                                   num_raster_threads,
                                   Picture::RECORD_NORMALLY);
+        // 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_ &=

[alokp, 2014/04/09 18:28:27]

enne@: I need to move this flag to the impl thread because
SkPicture::suitableForGpuRasterization needs the GrContext. Is there a way to
detect whenever a PicturePileImpl is updated? Otherwise I may need to traverse
through all pictures in the pile after each commit.

[enne (OOO), 2014/04/09 18:32:53]

PicturePileImpls are never updated, only overwritten.  I think you could just
move this flag to the base class and copy it in each of the ctors and copy ctors
there.

+            picture->IsSuitableForGpuRasterization();
         base::TimeDelta duration =
             stats_instrumentation->EndRecording(start_time);
         best_duration = std::min(duration, best_duration);