Introduce Property Trees

cc/trees/layer_tree_host_unittest_no_message_loop.cc

Index: cc/trees/layer_tree_host_unittest_no_message_loop.cc
diff --git a/cc/trees/layer_tree_host_unittest_no_message_loop.cc b/cc/trees/layer_tree_host_unittest_no_message_loop.cc
index 9e6611a8be63d1c2c13b9f84679fdc417e94527b..102e8ac9e46fd0946e88eafb2d0de91416a9d158 100644
--- a/cc/trees/layer_tree_host_unittest_no_message_loop.cc
+++ b/cc/trees/layer_tree_host_unittest_no_message_loop.cc
@@ -101,6 +101,7 @@ class LayerTreeHostNoMessageLoopTest
   void SetupLayerTreeHost() {
     LayerTreeSettings settings;
     settings.single_thread_proxy_scheduler = false;
+    settings.verify_property_trees = true;

[enne (OOO), 2014/12/16 19:54:28]

Defaulting this property to false does mean that we're not going to end up with
accidentally verifying in production, but is this really all of them?

[Ian Vollick, 2014/12/16 21:28:18]

There are a number of changes in this CL that ensure that we get coverage
(another place to look is the CalcDrawPropsInputForTesting where I set this
value to true). I ensured that the coverage was sufficient by CHECK'ing that
we'd set the verify_property_trees value to true and making sure the tests all
passed.

I thought that the default-off/turn-on-for-tests was a safer design than
default-on/disable-for-production given all the ways we initialize in our
various configurations.

     layer_tree_host_ = LayerTreeHost::CreateSingleThreaded(
         this, this, nullptr, nullptr, settings, nullptr, nullptr);
     layer_tree_host_->SetViewportSize(size_);