cc: Throttle swaps in Scheduler instead of OutputSurface

cc/test/fake_output_surface.cc

Index: cc/test/fake_output_surface.cc
diff --git a/cc/test/fake_output_surface.cc b/cc/test/fake_output_surface.cc
index 920b68940c7aea80b23534c60436050206a5b537..341c5f522a6c22c9febc2490db301e3850cc37a6 100644
--- a/cc/test/fake_output_surface.cc
+++ b/cc/test/fake_output_surface.cc
@@ -63,6 +63,12 @@ FakeOutputSurface::FakeOutputSurface(
 FakeOutputSurface::~FakeOutputSurface() {}
 
 void FakeOutputSurface::SwapBuffers(CompositorFrame* frame) {
+  // In unit tests we sometimes lose the context synchronously during a draw,
+  // so we abort the swap here if that's the case. Real implementations of
+  // OutputSurface should DCHECK that is_lost_ is false.
+  if (is_lost_)

[brianderson, 2014/04/12 00:09:58]

I decided to DCHECK for all other OutputSurface implementations.

[danakj, 2014/04/14 18:14:51]

Hm, there's no point in a unit test that can't happen in reality. We should
understand why these tests can't actually happen and remove them/change them to
match reality.

In single thread, right now we check for lost context after drawing, and return
false from DoComposite() to avoid swapping.

We could check in the ThreadProxy to get similar behaviour. Right now I don't
think we do, so we could lose the context during draw but do the swap hitting
the DCHECK?

But why do we care if we SwapBuffers on a lost surface anyway?

[brianderson, 2014/04/16 22:41:53]

I'm going to remove the is_lost_ checks.

+    return;
+
   if (frame->software_frame_data || frame->delegated_frame_data ||
       !context_provider()) {
     frame->AssignTo(&last_sent_frame_);