viz: Move surface_synchronization_unittest to components/viz/service/frame_sinks

Surface synchronization unit tests use CompositorFrameSinkSupport and
FrameSinkManager which makes them part of the frame_sinks layer.
This CL moves the file to components/viz/service/frame_sinks,
updating includes, namespaces and forward declarations as appropriate.

Bug: 722935
TBR: piman@chromium.org
Change-Id: Ic8395dd78dfdcbe10caaef8377998843d01bad0f
Reviewed-on: https://chromium-review.googlesource.com/572385Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Commit-Queue: Fady Samuel <fsamuel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487214}

cc/BUILD.gn

@@ -838,7 +838,6 @@ cc_test("cc_unittests") {
     "animation/transform_operations_unittest.cc",
     "surfaces/surface_hittest_unittest.cc",
     "surfaces/surface_manager_ref_unittest.cc",
-    "surfaces/surface_synchronization_unittest.cc",
     "surfaces/surface_unittest.cc",
 
     # Setup.

cc/surfaces/surface_manager.h

@@ -33,6 +33,12 @@
 #include <string>
 #endif
 
+namespace viz {
+namespace test {
+class SurfaceSynchronizationTest;
+}
+}  // namespace viz
+
 namespace cc {
 
 struct BeginFrameAck;
@@ -40,10 +46,6 @@ struct BeginFrameArgs;
 class CompositorFrame;
 class Surface;
 
-namespace test {
-class SurfaceSynchronizationTest;
-}
-
 class CC_SURFACES_EXPORT SurfaceManager {
  public:
   enum class LifetimeType {
@@ -184,7 +186,7 @@ class CC_SURFACES_EXPORT SurfaceManager {
   }
 
  private:
-  friend class test::SurfaceSynchronizationTest;
+  friend class viz::test::SurfaceSynchronizationTest;
   friend class SurfaceManagerRefTest;
 
   using SurfaceIdSet = std::unordered_set<viz::SurfaceId, viz::SurfaceIdHash>;

components/viz/service/BUILD.gn

@@ -138,6 +138,7 @@ viz_source_set("unit_tests") {
     "frame_sinks/direct_layer_tree_frame_sink_unittest.cc",
     "frame_sinks/frame_sink_manager_unittest.cc",
     "frame_sinks/referenced_surface_tracker_unittest.cc",
+    "frame_sinks/surface_synchronization_unittest.cc",
     "hit_test/hit_test_aggregator_unittest.cc",
   ]