cc: Move blend_mode to the effect tree

cc/layers/layer_impl.h

Index: cc/layers/layer_impl.h
diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index eef15e78d508376958fe31bab0b595dc1bd66215..66acc46f24c692c618bd4e5500d1364f09d34e1e 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -212,15 +212,10 @@ class CC_EXPORT LayerImpl {
   void SetMutableProperties(uint32_t properties);
   uint32_t mutable_properties() const { return mutable_properties_; }
 
-  void SetBlendMode(SkXfermode::Mode);
-  SkXfermode::Mode blend_mode() const { return blend_mode_; }
   void set_draw_blend_mode(SkXfermode::Mode blend_mode) {
     draw_blend_mode_ = blend_mode;
   }
   SkXfermode::Mode draw_blend_mode() const { return draw_blend_mode_; }
-  bool uses_default_blend_mode() const {
-    return blend_mode_ == SkXfermode::kSrcOver_Mode;
-  }
 
   void SetPosition(const gfx::PointF& position);
   gfx::PointF position() const { return position_; }
@@ -541,9 +536,6 @@ class CC_EXPORT LayerImpl {
   SkColor background_color_;
   SkColor safe_opaque_background_color_;
 
-  SkXfermode::Mode blend_mode_;
-  // draw_blend_mode may be different than blend_mode_,
-  // when a RenderSurface re-parents the layer's blend_mode.
   SkXfermode::Mode draw_blend_mode_;
   gfx::PointF position_;
   gfx::Transform transform_;