cc: Don't swap PictureLayerTilingSet on activate.

cc/resources/picture_layer_tiling_perftest.cc

Index: cc/resources/picture_layer_tiling_perftest.cc
diff --git a/cc/resources/picture_layer_tiling_perftest.cc b/cc/resources/picture_layer_tiling_perftest.cc
index 3944e4698dc92fa6a4144d04083ff3402ad64f49..cce444442842069f1fdeeb79657a344dfe3c91cf 100644
--- a/cc/resources/picture_layer_tiling_perftest.cc
+++ b/cc/resources/picture_layer_tiling_perftest.cc
@@ -57,9 +57,7 @@ class PictureLayerTilingPerfTest : public testing::Test {
   void RunInvalidateTest(const std::string& test_name, const Region& region) {
     timer_.Reset();
     do {
-      picture_layer_tiling_->UpdateTilesToCurrentRasterSource(
-          picture_layer_tiling_client_.raster_source(), region,
-          picture_layer_tiling_->tiling_size());
+      picture_layer_tiling_->Invalidate(region);
       timer_.NextLap();
     } while (!timer_.HasTimeLimitExpired());