Splitting DidSwap in cc::SwapPromise into WillSwap and DidSwap

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 3a475e110ff5bec9e56315a035f3a5a68f113d6e..b88e305669c0d8c771c797d86d67ee8e8df80b37 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -1515,10 +1515,17 @@ void LayerTreeImpl::AppendSwapPromises(
 
 void LayerTreeImpl::FinishSwapPromises(CompositorFrameMetadata* metadata) {
   for (const auto& swap_promise : swap_promise_list_)
-    swap_promise->DidSwap(metadata);
+    swap_promise->WillSwap(metadata);
+  for (const auto& swap_promise : pinned_swap_promise_list_)
+    swap_promise->WillSwap(metadata);
+}
+
+void LayerTreeImpl::ClearSwapPromises() {
+  for (const auto& swap_promise : swap_promise_list_)
+    swap_promise->DidSwap();
   swap_promise_list_.clear();
   for (const auto& swap_promise : pinned_swap_promise_list_)
-    swap_promise->DidSwap(metadata);
+    swap_promise->DidSwap();
   pinned_swap_promise_list_.clear();
 }