Implement RenderPass StructTraits

cc/ipc/quads.mojom

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module cc.mojom;
 
 import "cc/ipc/filter_operations.mojom";
 import "cc/ipc/render_pass_id.mojom";
 import "cc/ipc/surface_id.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
@@ skipping 106 matching lines @@
   // Allows changing the rect that gets drawn to make it smaller. This value
   // should be clipped to |rect|. This rect lives in content space.
   gfx.mojom.Rect visible_rect;
 
   // Allows changing the rect that gets drawn to make it smaller. This value
   // should be clipped to |rect|. This rect lives in content space.
   bool needs_blending;
 
   // Index into the containing pass' shared quad state array which has state
   // (transforms etc) shared by multiple quads.
-  uint32 shared_quad_state_index;
+  // TODO(fsamuel): This is not currently used because we store the
+  // indicies to SharedQuadStates in a separate array. This is more expensive
+  // than storing them inline here, but we need support for context propagation
+  // in Mojo StructTraits in order to store the sqs index here.
+  //uint32 shared_quad_state_index;
 
   // Only one of the following will be set, depending on the material.
   DebugBorderQuadState? debug_border_quad_state;
   RenderPassQuadState? render_pass_quad_state;
   SolidColorQuadState? solid_color_quad_state;
   SurfaceQuadState? surface_quad_state;
   TextureQuadState? texture_quad_state;
   TileQuadState? tile_quad_state;
   StreamVideoQuadState? stream_video_quad_state;
   YUVVideoQuadState? yuv_video_quad_state;
 };
 
 struct QuadList {
   array<Material> quad_types;
   array<DrawQuad> quads;
 };