Add a flag to disable partial raster in renderer

cc/tiles/picture_layer_tiling.cc

Index: cc/tiles/picture_layer_tiling.cc
diff --git a/cc/tiles/picture_layer_tiling.cc b/cc/tiles/picture_layer_tiling.cc
index be8a7940f7048522a7e13e928e3b50a4f71c513c..8e2aa02f9b8e170c1c2d5f9711d82105accf445d 100644
--- a/cc/tiles/picture_layer_tiling.cc
+++ b/cc/tiles/picture_layer_tiling.cc
@@ -141,7 +141,8 @@ void PictureLayerTiling::CreateMissingTilesInLiveTilesRect() {
       // If this is the pending tree, then the active twin tiling may contain
       // the previous content ID of these tiles. In that case, we need only
       // partially raster the tile content.
-      if (tile && invalidation && TilingMatchesTileIndices(active_twin)) {
+      if (client_->EnablePartialRaster() && tile && invalidation &&
+          TilingMatchesTileIndices(active_twin)) {
         if (const Tile* old_tile =
                 active_twin->TileAt(key.index_x, key.index_y)) {
           gfx::Rect tile_rect = tile->content_rect();