cc/blimp: Set up the framework for state serialization.

cc/blimp/layer_tree_host_remote.cc

Index: cc/blimp/layer_tree_host_remote.cc
diff --git a/cc/blimp/layer_tree_host_remote.cc b/cc/blimp/layer_tree_host_remote.cc
index 5f123e2b06867ec6ffb33cc2a4eb223d08be67e2..d0157256051303bc310e5429da5a9f5aad161ea9 100644
--- a/cc/blimp/layer_tree_host_remote.cc
+++ b/cc/blimp/layer_tree_host_remote.cc
@@ -10,6 +10,8 @@
 #include "cc/blimp/compositor_proto_state_sink.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/output/compositor_frame_sink.h"
+#include "cc/proto/compositor_message.pb.h"
+#include "cc/proto/layer_tree_host.pb.h"
 #include "cc/trees/layer_tree.h"
 #include "cc/trees/layer_tree_host_client.h"
 #include "cc/trees/layer_tree_host_common.h"
@@ -374,10 +376,13 @@ void LayerTreeHostRemote::BeginMainFrame() {
     return;
   }
 
-  // TODO(khushalsagar): Serialize current state/reset dirty state tracking and
-  // return the result to the state sink instead.
   std::unique_ptr<CompositorProtoState> compositor_state =
       base::MakeUnique<CompositorProtoState>();
+  compositor_state->swap_promises = swap_promise_manager_.TakeSwapPromises();
+  compositor_state->compositor_message =
+      base::MakeUnique<proto::CompositorMessage>();
+  SerializeCurrentState(
+      compositor_state->compositor_message->mutable_layer_tree_host());
   compositor_proto_state_sink_->ProcessCompositorStateUpdate(
       std::move(compositor_state));
 
@@ -415,4 +420,18 @@ void LayerTreeHostRemote::DispatchDrawAndSwapCallbacks() {
   client_->DidCompleteSwapBuffers();
 }
 
+void LayerTreeHostRemote::SerializeCurrentState(
+    proto::LayerTreeHost* layer_tree_host_proto) {
+  // Serialize the LayerTree.
+  layer_tree_->ToProtobuf(layer_tree_host_proto->mutable_layer_tree(), true);

[ajuma, 2016/09/29 20:55:33]

Instead of passing |true| here, please create a variable with a good name
(perhaps "inputs_only"), set that variable's value to true, and pass that
variable as the argument. That'll make this more readable. An alternative would
be to change the type of the second argument to an enum. (And same comment for
the other callsites of methods with boolean arguments added in this CL.)

[Khushal, 2016/10/04 09:11:50]

Done.

+
+  // Serialize the dirty layers.
+  for (auto* layer : layer_tree_->LayersThatShouldPushProperties())
+    layer->ToLayerPropertiesProto(
+        layer_tree_host_proto->mutable_layer_updates(), true);
+  layer_tree_->LayersThatShouldPushProperties().clear();
+
+  // TODO(khushalsagar): Deal with picture caching.
+}
+
 }  // namespace cc