Add SwapPromise support to LayerTreeHost and LayerTreeImpl

cc/trees/layer_tree_host.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/layer_tree_host.h"
 
 #include <algorithm>
 #include <stack>
 #include <string>
 
@@ skipping 367 matching lines @@
     sync_tree->set_sent_page_scale_delta(1.f);
   }
 
   sync_tree->SetPageScaleFactorAndLimits(page_scale_factor_,
                                          min_page_scale_factor_,
                                          max_page_scale_factor_);
   sync_tree->SetPageScaleDelta(page_scale_delta / sent_page_scale_delta);
   sync_tree->SetLatencyInfo(latency_info_);
   latency_info_.Clear();
 
+  sync_tree->PassSwapPromises(&swap_promise_list_);
+
   host_impl->SetViewportSize(device_viewport_size_);
   host_impl->SetOverdrawBottomHeight(overdraw_bottom_height_);
   host_impl->SetDeviceScaleFactor(device_scale_factor_);
   host_impl->SetDebugState(debug_state_);
   if (pending_page_scale_animation_) {
     host_impl->StartPageScaleAnimation(
         pending_page_scale_animation_->target_offset,
         pending_page_scale_animation_->use_anchor,
         pending_page_scale_animation_->scale,
         pending_page_scale_animation_->duration);
@@ skipping 863 matching lines @@
 }
 
 bool LayerTreeHost::ScheduleMicroBenchmark(
     const std::string& benchmark_name,
     scoped_ptr<base::Value> value,
     const MicroBenchmark::DoneCallback& callback) {
   return micro_benchmark_controller_.ScheduleRun(
       benchmark_name, value.Pass(), callback);
 }
 
+void LayerTreeHost::QueueSwapPromise(scoped_ptr<SwapPromise> swap_promise) {
+  if (proxy_->HasImplThread()) {
+    DCHECK(proxy_->CommitRequested() || proxy_->BeginMainFrameRequested());
+  }
+  if (swap_promise_list_.size() > kMaxQueuedSwapPromiseNumber)
+    BreakSwapPromises(SwapPromise::SWAP_PROMISE_LIST_OVERFLOW);
+  swap_promise_list_.push_back(swap_promise.Pass());
+}
+
+void LayerTreeHost::BreakSwapPromises(SwapPromise::DidNotSwapReason reason) {
+  for (size_t i = 0; i < swap_promise_list_.size(); i++) {
+    DCHECK(swap_promise_list_[i]);

[danakj, 2013/11/26 16:24:37]

Can you DCHECK this when they are added (QueueSwapPromise) instead of here? That
will find anything adding a NULL swap promise to the list faster, and give a
better stack trace. DCHECK before a null deref doesn't add too much value.

[Yufeng Shen (Slow to review), 2013/11/26 17:30:34]

Done.

+    swap_promise_list_[i]->DidNotSwap(reason);
+  }
+  swap_promise_list_.clear();
+}
+
 }  // namespace cc