cc: Clean up RecordingSource API

cc/proto/layer.proto

Index: cc/proto/layer.proto
diff --git a/cc/proto/layer.proto b/cc/proto/layer.proto
index c8ae18b85d081cacd125b25de0799e12cfde2fd9..c75c1d4d692c167692a48bea5028f98857a0303f 100644
--- a/cc/proto/layer.proto
+++ b/cc/proto/layer.proto
@@ -4,10 +4,10 @@
 
 syntax = "proto2";
 
+import "display_item.proto";
 import "layer_position_constraint.proto";
 import "point3f.proto";
 import "pointf.proto";
-import "recording_source.proto";
 import "region.proto";
 import "rect.proto";
 import "scroll_offset.proto";
@@ -130,13 +130,23 @@ message BaseLayerProperties {
 }
 
 message PictureLayerProperties {
-  optional RecordingSource recording_source = 1;
-  optional Region invalidation = 2;
-  optional Rect last_updated_visible_layer_rect = 3;
-  optional bool is_mask = 4;
-  optional bool nearest_neighbor = 5;
-
-  optional int64 update_source_frame_number = 6;
+  optional Region invalidation = 1;
+  optional Rect last_updated_visible_layer_rect = 2;
+  optional bool is_mask = 3;
+  optional bool nearest_neighbor = 4;
+
+  optional int64 update_source_frame_number = 5;
+
+  optional Rect recorded_viewport = 6;
+  optional Size size = 7;
+  optional int64 slow_down_raster_scale_factor_for_debug = 8;
+  optional bool generate_discardable_images_metadata = 9;
+  optional bool requires_clear = 10;
+  optional bool is_solid_color = 11;
+  optional bool clear_canvas_with_debug_color = 12;
+  optional uint64 solid_color = 13;
+  optional uint64 background_color = 14;
+  optional DisplayItemList display_list = 15;
 }
 
 message SolidColorScrollbarLayerProperties {