cc: Add functions for getting absolute tile indices.

cc/base/tiling_data.cc

Index: cc/base/tiling_data.cc
diff --git a/cc/base/tiling_data.cc b/cc/base/tiling_data.cc
index 98397e55ccfbb918b117e8c260ce088da6eabb9e..f8aa8351109b8498d0678619f045bbc02d565a41 100644
--- a/cc/base/tiling_data.cc
+++ b/cc/base/tiling_data.cc
@@ -91,6 +91,36 @@ int TilingData::TileYIndexFromSrcCoord(int src_position) const {
   return std::min(std::max(y, 0), num_tiles_y_ - 1);
 }
 
+int TilingData::TileAbsoluteXIndexFromSrcCoord(int src_position) const {
+  int inner_tile_width = max_texture_size_.width() - 2 * border_texels_;
+  if (inner_tile_width <= 0)
+    return 0;
+
+  int max_width = inner_tile_width * num_tiles_x_ + 2 * border_texels_;
+  if (src_position >= 0 && src_position < max_width)
+    return TileXIndexFromSrcCoord(src_position);
+
+  if (src_position >= max_width)
+    return num_tiles_x_ + (src_position - max_width) / inner_tile_width;
+
+  return (src_position + 1) / inner_tile_width - 1;
+}
+
+int TilingData::TileAbsoluteYIndexFromSrcCoord(int src_position) const {
+  int inner_tile_height = max_texture_size_.height() - 2 * border_texels_;
+  if (inner_tile_height <= 0)
+    return 0;
+
+  int max_height = inner_tile_height * num_tiles_y_ + 2 * border_texels_;
+  if (src_position >= 0 && src_position < max_height)
+    return TileYIndexFromSrcCoord(src_position);
+
+  if (src_position >= max_height)
+    return num_tiles_y_ + (src_position - max_height) / inner_tile_height;
+
+  return (src_position + 1) / inner_tile_height - 1;
+}
+
 int TilingData::FirstBorderTileXIndexFromSrcCoord(int src_position) const {
   if (num_tiles_x_ <= 1)
     return 0;