cc: Low quality support for low res tiles

cc/resources/managed_tile_state.h

Index: cc/resources/managed_tile_state.h
diff --git a/cc/resources/managed_tile_state.h b/cc/resources/managed_tile_state.h
index 2305b263dba00a72527571482631f777cfe7d7db..1879ed185aaffc6af36c5728e2d2349e1944e8ef 100644
--- a/cc/resources/managed_tile_state.h
+++ b/cc/resources/managed_tile_state.h
@@ -5,6 +5,8 @@
 #ifndef CC_RESOURCES_MANAGED_TILE_STATE_H_
 #define CC_RESOURCES_MANAGED_TILE_STATE_H_
 
+#include <map>
+
 #include "base/memory/scoped_ptr.h"
 #include "cc/resources/platform_color.h"
 #include "cc/resources/raster_worker_pool.h"
@@ -75,6 +77,8 @@ class CC_EXPORT ManagedTileState {
         return resource_;
       }
 
+      bool ShouldBeUpdatedBy(TileRasterMode new_mode) const;
+
     private:
       friend class TileManager;
       friend class Tile;
@@ -95,6 +99,8 @@ class CC_EXPORT ManagedTileState {
         resource_id_ = 0;
       }
 
+      void PushPropertiesTo(TileVersion* destination);
+
       Mode mode_;
       SkColor solid_color_;
 
@@ -105,6 +111,8 @@ class CC_EXPORT ManagedTileState {
       scoped_ptr<ResourcePool::Resource> resource_;
       GLenum resource_format_;
       bool forced_upload_;
+      TileRasterMode raster_mode_;
+      RasterWorkerPool::RasterTask raster_task_;
   };
 
 
@@ -115,9 +123,12 @@ class CC_EXPORT ManagedTileState {
 
   // Persisted state: valid all the time.
   TileVersion tile_version;

[reveman, 2013/06/05 14:25:13]

Why not just replace |tile_version| with:
typedef std::map<TileRasterMode, TileVersion> TileVersionMap;
TileVersionMap tile_versions;
or maybe:
TileVersion tile_versions[NUM_RASTER_MODES];

The tile manager code would essentially be the same as before expect anywhere
you access |tile_version| you would do tile_versions[raster_mode] instead.

"TileVersion tile_versions[NUM_RASTER_MODES]" is probably much better than using
std::map. The advantage of the map would be that you could save some memory when
we have a lot of different tile versions but that's not the case right now and
the simple array is likely much more efficient.

+
+  typedef std::map<TileRasterMode, TileVersion*> TileVersionMap;
+  TileVersionMap pending_tile_versions;
+
   bool picture_pile_analyzed;
   PicturePileImpl::Analysis picture_pile_analysis;
-  RasterWorkerPool::RasterTask raster_task;
 
   // Ephemeral state, valid only during TileManager::ManageTiles.
   bool is_in_never_bin_on_both_trees() const {