Move BSP tree perf test to cc/output/.

It's weird to have a perf test for BSP tree stuff in the same file
as perf tests for CalcDrawProps.

R=enne
BUG=606056
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_precise_blink_rel

Review-Url: https://codereview.chromium.org/2320883002
Cr-Commit-Position: refs/heads/master@{#417357}

diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index b098d79..3562e55 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn

@@ -998,6 +998,7 @@
     "ipc/cc_serialization_perftest.cc",
     "layers/layer_perftest.cc",
     "layers/picture_layer_impl_perftest.cc",
+    "output/bsp_tree_perftest.cc",
     "quads/draw_quad_perftest.cc",
     "raster/raster_buffer_provider_perftest.cc",
     "raster/task_graph_runner_perftest.cc",