Splitting DidSwap in cc::SwapPromise into WillSwap and DidSwap

content/test/layouttest_support.cc

Index: content/test/layouttest_support.cc
diff --git a/content/test/layouttest_support.cc b/content/test/layouttest_support.cc
index 58614e6c86f9a057f0935b5d652b942ecce6412e..7c75ed0d574b02d9bd6a2c6be1c4d42fcf3c6739 100644
--- a/content/test/layouttest_support.cc
+++ b/content/test/layouttest_support.cc
@@ -305,10 +305,11 @@ class CopyRequestSwapPromise : public cc::SwapPromise {
     DCHECK(compositor_frame_sink_from_commit_);
   }
   void DidActivate() override {}
-  void DidSwap(cc::CompositorFrameMetadata*) override {
+  void WillSwap(cc::CompositorFrameMetadata*) override {
     compositor_frame_sink_from_commit_->RequestCopyOfOutput(
         std::move(copy_request_));
   }
+  void DidSwap() override {}
   DidNotSwapAction DidNotSwap(DidNotSwapReason r) override {
     // The compositor should always swap in layout test mode.
     NOTREACHED() << "did not swap for reason " << r;