Allow binding multiple textures to one DC Layer overlay.

ui/gl/dc_renderer_layer_params.h

 // Copyright 2017 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.
 
 #ifndef UI_GL_DC_RENDERER_LAYER_PARAMS_H_
 #define UI_GL_DC_RENDERER_LAYER_PARAMS_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/transform.h"
 #include "ui/gl/gl_export.h"
 
 namespace gl {
 class GLImage;
 }
 
 namespace ui {
 
 struct GL_EXPORT DCRendererLayerParams {
   DCRendererLayerParams(bool is_clipped,
                         const gfx::Rect clip_rect,
                         int z_order,
                         const gfx::Transform& transform,
-                        gl::GLImage* image,
+                        std::vector<scoped_refptr<gl::GLImage>> image,
                         const gfx::RectF& contents_rect,
                         const gfx::Rect& rect,
                         unsigned background_color,
                         unsigned edge_aa_mask,
                         float opacity,
                         unsigned filter);
   DCRendererLayerParams(const DCRendererLayerParams& other);
   ~DCRendererLayerParams();
 
   bool is_clipped;
   const gfx::Rect clip_rect;
   int z_order;
   const gfx::Transform transform;
-  scoped_refptr<gl::GLImage> image;
+  std::vector<scoped_refptr<gl::GLImage>> image;
   const gfx::RectF contents_rect;
   const gfx::Rect rect;
   unsigned background_color;
   unsigned edge_aa_mask;
   float opacity;
   unsigned filter;
 
   // This is a subset of cc::FilterOperation::FilterType.
   enum class FilterEffectType : uint32_t {
     GRAYSDCLE,
@@ skipping 16 matching lines @@
     SkColor drop_shadow_color = 0;
   };
   using FilterEffects = std::vector<FilterEffect>;
 
   FilterEffects filter_effects;
 };
 
 }  // namespace ui
 
 #endif  // UI_GL_DC_RENDERER_LAYER_PARAMS_H_