Add SwapPromise support to LayerTreeHost and LayerTreeImpl

cc/trees/single_thread_proxy.cc

 // Copyright 2011 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/trees/single_thread_proxy.h"
 
 #include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/output/context_provider.h"
@@ skipping 374 matching lines @@
 
       // This CapturePostTasks should be destroyed before
       // DidCommitAndDrawFrame() is called since that goes out to the embedder,
       // and we want the embedder to receive its callbacks before that.
       // NOTE: This maintains consistent ordering with the ThreadProxy since
       // the DidCommitAndDrawFrame() must be post-tasked from the impl thread
       // there as the main thread is not blocked, so any posted tasks inside
       // the swap buffers will execute first.
       BlockingTaskRunner::CapturePostTasks blocked;
 
-      layer_tree_host_impl_->SwapBuffers(frame);
+      bool did_swap = layer_tree_host_impl_->SwapBuffers(frame);
+      if (did_swap)
+        layer_tree_host_impl_->active_tree()->FinishSwapPromise();

[danakj, 2013/11/13 23:22:09]

Why doesn't LTHI do this directly inside SwapBuffers?

[Yufeng Shen (Slow to review), 2013/11/14 22:09:55]

Done.

+      else
+        layer_tree_host_impl_->active_tree()->BreakSwapPromise(
+            SwapPromise::SWAP_FAILS);
     }
     DidSwapFrame();
   }
 }
 
 scoped_ptr<base::Value> SingleThreadProxy::AsValue() const {
   scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
   {
     // The following line casts away const modifiers because it is just
     // setting debug state. We still want the AsValue() function and its
@@ skipping 136 matching lines @@
 void SingleThreadProxy::DidSwapFrame() {
   if (next_frame_is_newly_committed_frame_) {
     next_frame_is_newly_committed_frame_ = false;
     layer_tree_host_->DidCommitAndDrawFrame();
   }
 }
 
 bool SingleThreadProxy::CommitPendingForTesting() { return false; }
 
 }  // namespace cc