cc: Remove code for drawing checkerboard quads, it's not used.

cc/output/shader.h

Index: cc/output/shader.h
diff --git a/cc/output/shader.h b/cc/output/shader.h
index d692a123cd79109b8885b1b3fce9b0292962b21a..326eb67b534fc9c39566d154ca4bc8ee2852ab8a 100644
--- a/cc/output/shader.h
+++ b/cc/output/shader.h
@@ -868,31 +868,6 @@ class FragmentShaderColorAA : public FragmentTexBlendMode {
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderColorAA);
 };
 
-class FragmentShaderCheckerboard : public FragmentTexBlendMode {
- public:
-  FragmentShaderCheckerboard();
-  std::string GetShaderString(
-      TexCoordPrecision precision, SamplerType sampler) const;
-  static std::string GetShaderHead();
-  static std::string GetShaderBody();
-
-  void Init(gpu::gles2::GLES2Interface* context,
-            unsigned program,
-            int* base_uniform_index);
-  int alpha_location() const { return alpha_location_; }
-  int tex_transform_location() const { return tex_transform_location_; }
-  int frequency_location() const { return frequency_location_; }
-  int color_location() const { return color_location_; }
-
- private:
-  int alpha_location_;
-  int tex_transform_location_;
-  int frequency_location_;
-  int color_location_;
-
-  DISALLOW_COPY_AND_ASSIGN(FragmentShaderCheckerboard);
-};
-
 }  // namespace cc
 
 #endif  // CC_OUTPUT_SHADER_H_