cc: Remove OutputSurfaceClient::DidSwapBuffers().

content/renderer/android/synchronous_compositor_output_surface.cc

Index: content/renderer/android/synchronous_compositor_output_surface.cc
diff --git a/content/renderer/android/synchronous_compositor_output_surface.cc b/content/renderer/android/synchronous_compositor_output_surface.cc
index 7919e83ab878b30f6e8019809ec86b2974d74fd5..f0445322b2bc0712c4c348b2cd9b1ffab4f8b39c 100644
--- a/content/renderer/android/synchronous_compositor_output_surface.cc
+++ b/content/renderer/android/synchronous_compositor_output_surface.cc
@@ -198,11 +198,10 @@ void SynchronousCompositorOutputSurface::SwapBuffers(
   DCHECK(sync_client_);
 
   if (fallback_tick_running_) {
-    client_->DidSwapBuffers();
-    client_->DidSwapBuffersComplete();
     DCHECK(frame.delegated_frame_data->resource_list.empty());
     cc::ReturnedResourceArray return_resources;
     ReturnResources(return_resources);
+    did_swap_ = true;
     return;
   }
 
@@ -236,7 +235,6 @@ void SynchronousCompositorOutputSurface::SwapBuffers(
 
   sync_client_->SwapBuffers(output_surface_id_, std::move(swap_frame));
   DeliverMessages();
-  client_->DidSwapBuffers();
   did_swap_ = true;
 }
 
@@ -333,8 +331,12 @@ void SynchronousCompositorOutputSurface::InvokeComposite(
   did_swap_ = false;
   client_->OnDraw(adjusted_transform, viewport, clip, in_software_draw_);
 
-  if (did_swap_)
+  if (did_swap_) {
+    // This must happen after unwinding the stack and leaving the compositor.
+    // Usually it is a separate task but we just defer it until OnDraw completes
+    // instead.
     client_->DidSwapBuffersComplete();
+  }
 }
 
 void SynchronousCompositorOutputSurface::OnReclaimResources(