Add SwapPromise support to LayerTreeHost and LayerTreeImpl

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 15bd750b13e24e02122ecaeb8df7579b692fe4cf..dcae12c5077a0fd9c2d7ff06375e047d6600e8dc 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -20,6 +20,10 @@
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/vector2d_conversions.h"
 
+namespace {
+const size_t kMaxQueuedSwapPromiseNumber = 100;

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

Can we share these constants instead of duplicating? They need to be the same
size.

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

Moved to swap_promise.h

+}  // namespace
+
 namespace cc {
 
 LayerTreeImpl::LayerTreeImpl(LayerTreeHostImpl* layer_tree_host_impl)
@@ -122,6 +126,9 @@ void LayerTreeImpl::PushPropertiesTo(LayerTreeImpl* target_tree) {
 
   target_tree->SetLatencyInfo(latency_info_);
   latency_info_.Clear();
+
+  target_tree->TakeSwapPromise(&swap_promise_list_);
+
   target_tree->SetPageScaleFactorAndLimits(
       page_scale_factor(), min_page_scale_factor(), max_page_scale_factor());
   target_tree->SetPageScaleDelta(
@@ -708,6 +715,36 @@ void LayerTreeImpl::ClearLatencyInfo() {
   latency_info_.Clear();
 }
 
+void LayerTreeImpl::QueueSwapPromise(SwapPromise* swap_promise) {

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

Same comments here as in LTH

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

Done.

+  if (swap_promise_list_.size() > kMaxQueuedSwapPromiseNumber) {
+    NOTREACHED() << "LayerTreeImpl::swap_promise_list overflows";
+    BreakSwapPromise(SwapPromise::SWAP_PROMISE_LIST_OVERFLOW);
+  }
+  swap_promise_list_.push_back(swap_promise);
+}
+
+void LayerTreeImpl::TakeSwapPromise(
+    ScopedVector<SwapPromise>* new_swap_promise) {
+  swap_promise_list_.insert(swap_promise_list_.end(),
+                            new_swap_promise->begin(),
+                            new_swap_promise->end());
+  new_swap_promise->weak_clear();
+}
+
+void LayerTreeImpl::FinishSwapPromise() {
+  for (size_t i = 0; i < swap_promise_list_.size(); i++) {
+    swap_promise_list_[i]->DidSwap();
+  }
+  swap_promise_list_.clear();
+}
+
+void LayerTreeImpl::BreakSwapPromise(SwapPromise::DidNotSwapReason reason) {
+  for (size_t i = 0; i < swap_promise_list_.size(); i++) {
+    swap_promise_list_[i]->DidNotSwap(reason);
+  }
+  swap_promise_list_.clear();
+}
+
 void LayerTreeImpl::DidModifyTilePriorities() {
   layer_tree_host_impl_->DidModifyTilePriorities();
 }