cc: Do not ignore layers without valid priorities during eviction.

cc/layers/picture_layer_impl.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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 
@@ skipping 670 matching lines @@
 }
 
 PictureLayerTiling* PictureLayerImpl::GetRecycledTwinTiling(
     const PictureLayerTiling* tiling) {
   PictureLayerImpl* recycled_twin = GetRecycledTwinLayer();
   if (!recycled_twin || !recycled_twin->tilings_)
     return nullptr;
   return recycled_twin->tilings_->TilingAtScale(tiling->contents_scale());
 }
 
+TilePriority::PriorityBin PictureLayerImpl::GetMaxTilePriorityBin() const {
+  if (!HasValidTilePriorities())
+    return TilePriority::EVENTUALLY;
+  return TilePriority::NOW;
+}
+
 size_t PictureLayerImpl::GetMaxTilesForInterestArea() const {
   return layer_tree_impl()->settings().max_tiles_for_interest_area;
 }
 
 float PictureLayerImpl::GetSkewportTargetTimeInSeconds() const {
   float skewport_target_time_in_frames =
       layer_tree_impl()->use_gpu_rasterization()
           ? kGpuSkewportTargetTimeInFrames
           : kCpuSkewportTargetTimeInFrames;
   return skewport_target_time_in_frames *
@@ skipping 1021 matching lines @@
       PictureLayerTilingSet::TilingRange tiling_range = CurrentTilingRange();
       size_t current_tiling_range_offset = current_tiling_ - tiling_range.start;
       return tiling_range.end - 1 - current_tiling_range_offset;
     }
   }
   NOTREACHED();
   return 0;
 }
 
 }  // namespace cc