Splitting DidSwap in cc::SwapPromise into WillSwap and DidSwap

cc/trees/layer_tree_host_unittest.cc

Index: cc/trees/layer_tree_host_unittest.cc
diff --git a/cc/trees/layer_tree_host_unittest.cc b/cc/trees/layer_tree_host_unittest.cc
index 9384e8aff06d2fa0fb84ccfbd1e84f8311fdce06..52ff8e13412d9cfe546a59675eee4e7923bdaf33 100644
--- a/cc/trees/layer_tree_host_unittest.cc
+++ b/cc/trees/layer_tree_host_unittest.cc
@@ -4560,13 +4560,15 @@ class TestSwapPromise : public SwapPromise {
     result_->did_activate_called = true;
   }
 
-  void DidSwap(CompositorFrameMetadata* metadata) override {
+  void WillSwap(CompositorFrameMetadata* metadata) override {
     base::AutoLock lock(result_->lock);
     EXPECT_FALSE(result_->did_swap_called);
     EXPECT_FALSE(result_->did_not_swap_called);
     result_->did_swap_called = true;
   }
 
+  void DidSwap() override {}
+
   DidNotSwapAction DidNotSwap(DidNotSwapReason reason) override {
     base::AutoLock lock(result_->lock);
     EXPECT_FALSE(result_->did_swap_called);