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

cc/proto/layer_tree_host.proto

Index: cc/proto/layer_tree_host.proto
diff --git a/cc/proto/layer_tree_host.proto b/cc/proto/layer_tree_host.proto
index 7ceeb2dd030d974e7436c955719f3e00653424ae..d948606b90b2a99d580561eb46b5795ce44f927f 100644
--- a/cc/proto/layer_tree_host.proto
+++ b/cc/proto/layer_tree_host.proto
@@ -26,6 +26,11 @@ message LayerTreeHost {
   // Not all members of LayerTreeHost are serialized, as they are not helpful
   // for remote usage. See implementation of
   // cc::LayerTreeHost::ToProtobufForCommit for details.
+  optional LayerTree layer_tree = 36;
+  optional LayerUpdate layer_updates = 28;
+  optional SkPictures pictures = 38;
+
+  // TODO(khushalsagar): Remove these when crbug.com/648442

[ajuma, 2016/10/04 15:45:10]

nit: missing end of sentence :)

[Khushal, 2016/10/04 18:34:47]

Done.

   optional int32 source_frame_number = 3;
   optional int32 meta_information_sequence_number = 4;
   optional LayerTreeDebugState debug_state = 8;
@@ -35,7 +40,4 @@ message LayerTreeHost {
   optional bool next_commit_forces_redraw = 24;
   optional uint32 surface_client_id = 31;
   optional uint32 next_surface_sequence = 32;
-  optional LayerTree layer_tree = 36;
-  optional LayerUpdate layer_updates = 28;
-  optional SkPictures pictures = 38;
 }