Add logic to convert from RenderPassDrawQuads to CALayerOverlays.

ui/gl/ca_renderer_layer_params.h

 // Copyright 2016 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_CA_RENDERER_LAYER_PARAMS_H_
 #define UI_GL_CA_RENDERER_LAYER_PARAMS_H_
 
+#include <vector>
+
 #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 {
@@ skipping 17 matching lines @@
   const gfx::Rect clip_rect;
   unsigned sorting_context_id;
   const gfx::Transform transform;
   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 GL_EXPORT FilterEffectType {
+    GRAYSCALE,
+    SEPIA,
+    SATURATE,
+    HUE_ROTATE,
+    INVERT,
+    BRIGHTNESS,
+    CONTRAST,
+    OPACITY,
+    BLUR,
+    DROP_SHADOW,
+  };
+  struct GL_EXPORT FilterEffect {
+    FilterEffectType type = FilterEffectType::GRAYSCALE;
+
+    // For every filter other than DROP_SHADOW, the field |data[0]| is a float
+    // reinterpret casted to a int32_t. The rest of |data| is not used.
+    // For DROP_SHADOW, the 4 fields represent:
+    //   data[0]: The blur amount, reinterpret casted from a float.
+    //   data[1]: x offset.
+    //   data[2]: y offset.
+    //   data[3]: SkColor, reinterpret casted from a uint32_t.
+    int32_t data[4] = {0};

[ccameron, 2016/07/21 05:44:56]

I'd think it better to do:
  float amount = 0;
  gfx::PointF drop_shadow_offset;
  unsigned drop_shadow_color = 0;

If we need to do any sort of encoding to get this through the command buffer, we
should do that at the call site (I assume that's the motivation for the packing
here?).

[erikchen, 2016/07/21 16:28:04]

duh, good point. Done.

+  };
+  using FilterEffects = std::vector<FilterEffect>;
+
+  FilterEffects filter_effects;
 };
 
 }  // namespace ui
 
 #endif  // UI_GL_CA_RENDERER_LAYER_PARAMS_H_