Splitting DidSwap in cc::SwapPromise into WillSwap and DidSwap

cc/layers/surface_layer.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/surface_layer.h"
 
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/layers/surface_layer_impl.h"
 #include "cc/output/swap_promise.h"
 #include "cc/surfaces/surface_sequence_generator.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/swap_promise_manager.h"
 
 namespace cc {
 
 class SatisfySwapPromise : public SwapPromise {
  public:
   SatisfySwapPromise(SurfaceSequence sequence,
                      const SurfaceLayer::SatisfyCallback& satisfy_callback)
       : sequence_(sequence), satisfy_callback_(satisfy_callback) {}
 
   ~SatisfySwapPromise() override {}
 
  private:
   void DidActivate() override {}
-  void DidSwap(CompositorFrameMetadata* metadata) override {
+  void WillSwap(CompositorFrameMetadata* metadata) override {
     metadata->satisfies_sequences.push_back(sequence_.sequence);
   }
+  void DidSwap() override {}
 
   DidNotSwapAction DidNotSwap(DidNotSwapReason reason) override {
     satisfy_callback_.Run(sequence_);
     return DidNotSwapAction::BREAK_PROMISE;
   }
   int64_t TraceId() const override { return 0; }
 
   SurfaceSequence sequence_;
   SurfaceLayer::SatisfyCallback satisfy_callback_;
 
@@ skipping 76 matching lines @@
     return;
   DCHECK(destroy_sequence_.is_valid());
   std::unique_ptr<SatisfySwapPromise> satisfy(
       new SatisfySwapPromise(destroy_sequence_, satisfy_callback_));
   layer_tree_host()->GetSwapPromiseManager()->QueueSwapPromise(
       std::move(satisfy));
   destroy_sequence_ = SurfaceSequence();
 }
 
 }  // namespace cc