cc: Partial tile update for one-copy raster.

cc/resources/tile.cc

Index: cc/resources/tile.cc
diff --git a/cc/resources/tile.cc b/cc/resources/tile.cc
index 2faa6e48b2e4c2c4d4be306394b1c89170dcd1d7..f27ba2f37675d0ba499cb1961f8ad9aaec109fd2 100644
--- a/cc/resources/tile.cc
+++ b/cc/resources/tile.cc
@@ -13,7 +13,7 @@
 
 namespace cc {
 
-Tile::Id Tile::s_next_id_ = 0;
+Tile::Id Tile::s_next_id_ = 1;
 
 Tile::Tile(TileManager* tile_manager,
            RasterSource* raster_source,
@@ -35,6 +35,7 @@ Tile::Tile(TileManager* tile_manager,
       required_for_activation_(false),
       required_for_draw_(false),
       id_(s_next_id_++),
+      invalidated_id_(0),
       scheduled_priority_(0) {
   set_raster_source(raster_source);
 }