cc: Commit directly to active tree when using single thread.

cc/trees/single_thread_proxy.cc

Index: cc/trees/single_thread_proxy.cc
diff --git a/cc/trees/single_thread_proxy.cc b/cc/trees/single_thread_proxy.cc
index 7d5689f1ddb87903474126621bfcd6c1dd71f40d..66522eaa0c4df55bd6732e83eb08f33ac37fd270 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -82,6 +82,12 @@ bool SingleThreadProxy::IsStarted() const {
   return layer_tree_host_impl_;
 }
 
+bool SingleThreadProxy::CommitToActiveTree() const {
+  // With SingleThreadProxy we skip the pending tree and commit directly to the
+  // active tree.
+  return false;

[enne (OOO), 2015/01/28 01:14:53]

...false?!

[danakj, 2015/01/28 01:28:20]

Oh thats why my unittests started passing. thanks :D

+}
+
 void SingleThreadProxy::SetLayerTreeHostClientReady() {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetLayerTreeHostClientReady");
   // Scheduling is controlled by the embedder in the single thread case, so
@@ -250,9 +256,8 @@ void SingleThreadProxy::DoCommit() {
   }
 
   if (layer_tree_host_->settings().impl_side_painting) {
-    // TODO(enne): just commit directly to the active tree.
-    //
-    // Synchronously activate during commit to satisfy any potential
+    // Commit goes directly to the active tree, but we need to synchronously
+    // "activate" the tree still during commit to satisfy any potential
     // SetNextCommitWaitsForActivation calls.  Unfortunately, the tree
     // might not be ready to draw, so DidActivateSyncTree must set
     // the flag to force the tree to not draw until textures are ready.
@@ -433,8 +438,8 @@ void SingleThreadProxy::DidActivateSyncTree() {
   // Non-impl-side painting finishes commit in DoCommit.  Impl-side painting
   // defers until here to simulate SetNextCommitWaitsForActivation.
   if (layer_tree_host_impl_->settings().impl_side_painting) {
-    // This is required because NotifyReadyToActivate gets called when
-    // the pending tree is not actually ready in the SingleThreadProxy.
+    // This is required because NotifyReadyToActivate gets called immediately
+    // after commit since single thread commits directly to the active tree.
     layer_tree_host_impl_->SetRequiresHighResToDraw();
 
     CommitComplete();