Add logic to convert from RenderPassDrawQuads to CALayerOverlays.

ui/gl/ca_renderer_layer_params.h

Index: ui/gl/ca_renderer_layer_params.h
diff --git a/ui/gl/ca_renderer_layer_params.h b/ui/gl/ca_renderer_layer_params.h
index a6727b471384b5aadf25b21c6365a511e0ce67e5..78593e24934c8f64fba97234764ccd430126e49a 100644
--- a/ui/gl/ca_renderer_layer_params.h
+++ b/ui/gl/ca_renderer_layer_params.h
@@ -5,6 +5,8 @@
 #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"
@@ -42,6 +44,35 @@ struct GL_EXPORT CARendererLayerParams {
   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