cc: Implement UnionTraits for DrawQuads

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/shared_quad_state.mojom";
 import "cc/ipc/surface_id.mojom";
@@ skipping 79 matching lines @@
   uint32 y_plane_resource_id;
   uint32 u_plane_resource_id;
   uint32 v_plane_resource_id;
   uint32 a_plane_resource_id;
   YUVColorSpace color_space;
   float resource_offset;
   float resource_multiplier;
   uint32 bits_per_channel;
 };
 
 enum Material {

[yzshen1, 2016/08/09 18:29:53]

Could we also remove this definition?

[Fady Samuel, 2016/08/09 18:42:50]

Done.

-  INVALID,
   DEBUG_BORDER,
-  PICTURE_CONTENT,
   RENDER_PASS,
   SOLID_COLOR,
   STREAM_VIDEO_CONTENT,
   SURFACE_CONTENT,
   TEXTURE_CONTENT,
   TILED_CONTENT,
   YUV_VIDEO_CONTENT,
 };
 
+union DrawQuadState {
+  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 DrawQuad {
-  Material material;
-
   // This rect, after applying the quad_transform(), gives the geometry that
   // this quad should draw to. This rect lives in content space.
   gfx.mojom.Rect rect;
 
   // This specifies the region of the quad that is opaque. This rect lives in
   // content space.
   gfx.mojom.Rect opaque_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.
   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;
 
   // Optionally holds a SharedQuadState (transforms etc) shared by multiple
   // quads.
   SharedQuadState? sqs;
 
-  // 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;
+  DrawQuadState draw_quad_state;
 };