cc: Let skia veto gpu rasterization.

cc/resources/picture_pile.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/picture_pile.h"
 
 #include <algorithm>
 #include <limits>
 #include <vector>
 
@@ skipping 123 matching lines @@
   }
 
   *record_rects = vertical_clustering;
   return vertical_density;
 }
 
 }  // namespace
 
 namespace cc {
 
-PicturePile::PicturePile() {
-}
+PicturePile::PicturePile() : is_suitable_for_gpu_rasterization_(true) {}
 
 PicturePile::~PicturePile() {
 }
 
 bool PicturePile::Update(ContentLayerClient* painter,
                          SkColor background_color,
                          bool contents_opaque,
                          bool contents_fill_bounds_completely,
                          const Region& invalidation,
                          const gfx::Rect& visible_layer_rect,
@@ skipping 82 matching lines @@
     {
       base::TimeDelta best_duration = base::TimeDelta::Max();
       for (int i = 0; i < repeat_count; i++) {
         base::TimeTicks start_time = stats_instrumentation->StartRecording();
         picture = Picture::Create(record_rect,
                                   painter,
                                   tile_grid_info_,
                                   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);
       }
       int recorded_pixel_count =
           picture->LayerRect().width() * picture->LayerRect().height();
       stats_instrumentation->AddRecord(best_duration, recorded_pixel_count);
     }
 
     bool found_tile_for_recorded_picture = false;
@@ skipping 11 matching lines @@
     }
     DCHECK(found_tile_for_recorded_picture);
   }
 
   has_any_recordings_ = true;
   DCHECK(CanRasterSlowTileCheck(recorded_viewport_));
   return true;
 }
 
 }  // namespace cc