The great shader refactor: Delete all of the subclasses

cc/output/shader.cc

Index: cc/output/shader.cc
diff --git a/cc/output/shader.cc b/cc/output/shader.cc
index 6d6edb4bd3816730ce45f5d2637b111208760a7c..6fa09001859e40664a7a956789a7691842b73f3c 100644
--- a/cc/output/shader.cc
+++ b/cc/output/shader.cc
@@ -395,14 +395,14 @@ std::string VertexShaderBase::GetShaderString() const {
 
 FragmentShaderBase::FragmentShaderBase() {}
 
-std::string FragmentShaderBase::GetShaderString(TexCoordPrecision precision,
-                                                SamplerType sampler) const {
+std::string FragmentShaderBase::GetShaderString() const {
   // The AA shader values will use TexCoordPrecision.
+  TexCoordPrecision precision = tex_coord_precision_;
   if (has_aa_ && precision == TEX_COORD_PRECISION_NA)
     precision = TEX_COORD_PRECISION_MEDIUM;
   return SetFragmentTexCoordPrecision(
       precision, SetFragmentSamplerType(
-                     sampler, SetBlendModeFunctions(GetShaderSource())));
+                     sampler_type_, SetBlendModeFunctions(GetShaderSource())));
 }
 
 void FragmentShaderBase::Init(GLES2Interface* context,
@@ -481,7 +481,7 @@ void FragmentShaderBase::FillLocations(ShaderLocations* locations) const {
     locations->backdrop = backdrop_location_;
     locations->backdrop_rect = backdrop_rect_location_;
   }
-  if (mask_for_background())
+  if (mask_for_background_)
     locations->original_backdrop = original_backdrop_location_;
   if (has_mask_sampler_) {
     locations->mask_sampler = mask_sampler_location_;
@@ -519,7 +519,7 @@ std::string FragmentShaderBase::SetBlendModeFunctions(
   });
 
   std::string mixFunction;
-  if (mask_for_background()) {
+  if (mask_for_background_) {
     mixFunction = SHADER0([]() {
       vec4 MixBackdrop(TexCoordPrecision vec2 bgTexCoord, float mask) {
         vec4 backdrop = texture2D(s_backdropTexture, bgTexCoord);