cc: Change preraster/predecode split to be half of max skewport extent.

cc/tiles/prioritized_tile.h

Index: cc/tiles/prioritized_tile.h
diff --git a/cc/tiles/prioritized_tile.h b/cc/tiles/prioritized_tile.h
index 300cc83e13491631d440def658bcfc6ea6101efa..30159784cbc541eecacca5aa95407e86e9dfb573 100644
--- a/cc/tiles/prioritized_tile.h
+++ b/cc/tiles/prioritized_tile.h
@@ -23,7 +23,8 @@ class CC_EXPORT PrioritizedTile {
   PrioritizedTile(Tile* tile,
                   const PictureLayerTiling* source_tiling,
                   const TilePriority priority,
-                  bool is_occluded);
+                  bool is_occluded,
+                  bool is_process_for_images_only);
   ~PrioritizedTile();
 
   Tile* tile() const { return tile_; }
@@ -32,6 +33,9 @@ class CC_EXPORT PrioritizedTile {
   }
   const TilePriority& priority() const { return priority_; }
   bool is_occluded() const { return is_occluded_; }
+  bool is_process_for_images_only() const {
+    return is_process_for_images_only_;
+  }
 
   void AsValueInto(base::trace_event::TracedValue* value) const;
 
@@ -40,6 +44,7 @@ class CC_EXPORT PrioritizedTile {
   const PictureLayerTiling* source_tiling_ = nullptr;
   TilePriority priority_;
   bool is_occluded_ = false;
+  bool is_process_for_images_only_ = false;
 };
 
 }  // namespace cc