Make disable vsync run the renderer independently

cc/trees/layer_tree_host_perftest.cc

Index: cc/trees/layer_tree_host_perftest.cc
diff --git a/cc/trees/layer_tree_host_perftest.cc b/cc/trees/layer_tree_host_perftest.cc
index edf1213e0260976a36c8610598ade64a2038b57d..5cde4a174a80139f651b62960c1b8d9323028bf7 100644
--- a/cc/trees/layer_tree_host_perftest.cc
+++ b/cc/trees/layer_tree_host_perftest.cc
@@ -46,7 +46,6 @@ class LayerTreeHostPerfTest : public LayerTreeTest {
   }
 
   void InitializeSettings(LayerTreeSettings* settings) override {
-    settings->wait_for_beginframe_interval = false;

[enne (OOO), 2016/09/08 22:19:52]

disable_display_vsync creates an unthrottled begin frame source in
TestDelegatingOutputSurface, and the unthrottled begin frame source causes the
scheduler to do the right thing, so this can just be removed.

[enne (OOO), 2016/09/12 20:04:38]

This used unthrottled before but with the other changes in the patch to
BeginFrameSource, the scheduler still knows it's unthrottled.

[brianderson, 2016/09/12 21:01:06]

Ah, sorry I missed this comment. lgtm, but maybe add the comment to the code
before landing.

     settings->renderer_settings.disable_display_vsync = true;
   }