Update from https://crrev.com/304121

cc/output/shader.h

 // Copyright 2011 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 CC_OUTPUT_SHADER_H_
 #define CC_OUTPUT_SHADER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 21 matching lines @@
 
 enum SamplerType {
   SamplerTypeNA = 0,
   SamplerType2D = 1,
   SamplerType2DRect = 2,
   SamplerTypeExternalOES = 3,
   NumSamplerTypes = 4
 };
 
 enum BlendMode {
+  BlendModeNone,
   BlendModeNormal,
+  BlendModeScreen,
   BlendModeOverlay,
   BlendModeDarken,
   BlendModeLighten,
   BlendModeColorDodge,
   BlendModeColorBurn,
   BlendModeHardLight,
   BlendModeSoftLight,
   BlendModeDifference,
   BlendModeExclusion,
   BlendModeMultiply,
@@ skipping 245 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(VertexShaderVideoTransform);
 };
 
 class FragmentTexBlendMode {
  public:
   int backdrop_location() const { return backdrop_location_; }
   int backdrop_rect_location() const { return backdrop_rect_location_; }
 
   BlendMode blend_mode() const { return blend_mode_; }
   void set_blend_mode(BlendMode blend_mode) { blend_mode_ = blend_mode; }
-  bool is_default_blend_mode() const { return blend_mode_ == BlendModeNormal; }
+  bool has_blend_mode() const { return blend_mode_ != BlendModeNone; }
 
  protected:
   FragmentTexBlendMode();
 
   std::string SetBlendModeFunctions(std::string shader_string) const;
 
   int backdrop_location_;
   int backdrop_rect_location_;
 
  private:
@@ skipping 450 matching lines @@
   int tex_transform_location_;
   int frequency_location_;
   int color_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderCheckerboard);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_SHADER_H_