[cc] Plumb BeginFrameAcks through SurfaceManager to DisplayScheduler.

Plumbs the BeginFrameAcks from DidNotProduceFrame and
SubmitCompositorFrame through new SurfaceObserver methods from
CompositorFrameSinks to the DisplayScheduler.

Also replaces the expected surface damage heuristics previously used
by DisplayScheduler with tracking BeginFrame(Ack)s and surface damage.

This is work towards unified BeginFrame acknowledgments, see:
Tracking bug: https://crbug.com/697086
Design doc: http://bit.ly/beginframeacks

BUG=697086, 646774, 678119, 703079, 707513
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2854163003
Cr-Commit-Position: refs/heads/master@{#474989}

diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index 18e1856..cb966fd 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn

@@ -568,6 +568,8 @@
     "test/fake_scoped_ui_resource.h",
     "test/fake_scrollbar.cc",
     "test/fake_scrollbar.h",
+    "test/fake_surface_observer.cc",
+    "test/fake_surface_observer.h",
     "test/fake_surface_resource_holder_client.cc",
     "test/fake_surface_resource_holder_client.h",
     "test/fake_tile_manager.cc",