[mutter] cogl: glBlendFuncSeparate is always available

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 9cbf83d59c7e9610aed28a50b6312659e6a19b45
Author: Adam Jackson <ajax redhat com>
Date:   Tue Oct 22 19:30:16 2019 -0400

    cogl: glBlendFuncSeparate is always available
    
    So we don't need glBlendFunc.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/903

 cogl/cogl/driver/gl/cogl-pipeline-opengl.c    | 17 ++++-------------
 cogl/cogl/gl-prototypes/cogl-core-functions.h |  2 --
 2 files changed, 4 insertions(+), 15 deletions(-)
---
diff --git a/cogl/cogl/driver/gl/cogl-pipeline-opengl.c b/cogl/cogl/driver/gl/cogl-pipeline-opengl.c
index c764c054f..adda93567 100644
--- a/cogl/cogl/driver/gl/cogl-pipeline-opengl.c
+++ b/cogl/cogl/driver/gl/cogl-pipeline-opengl.c
@@ -474,7 +474,6 @@ _cogl_pipeline_flush_color_blend_alpha_depth_state (
       CoglPipelineBlendState *blend_state =
         &authority->big_state->blend_state;
 
-      /* GLES 1 only has glBlendFunc */
 #if defined(HAVE_COGL_GLES2) || defined(HAVE_COGL_GL)
       if (blend_factor_uses_constant (blend_state->blend_src_factor_rgb) ||
           blend_factor_uses_constant (blend_state
@@ -498,18 +497,10 @@ _cogl_pipeline_flush_color_blend_alpha_depth_state (
       GE (ctx, glBlendEquationSeparate (blend_state->blend_equation_rgb,
                                         blend_state->blend_equation_alpha));
 
-      if (ctx->glBlendFuncSeparate &&
-          (blend_state->blend_src_factor_rgb !=
-           blend_state->blend_src_factor_alpha ||
-           (blend_state->blend_dst_factor_rgb !=
-            blend_state->blend_dst_factor_alpha)))
-        GE (ctx, glBlendFuncSeparate (blend_state->blend_src_factor_rgb,
-                                      blend_state->blend_dst_factor_rgb,
-                                      blend_state->blend_src_factor_alpha,
-                                      blend_state->blend_dst_factor_alpha));
-      else
-        GE (ctx, glBlendFunc (blend_state->blend_src_factor_rgb,
-                              blend_state->blend_dst_factor_rgb));
+      GE (ctx, glBlendFuncSeparate (blend_state->blend_src_factor_rgb,
+                                    blend_state->blend_dst_factor_rgb,
+                                    blend_state->blend_src_factor_alpha,
+                                    blend_state->blend_dst_factor_alpha));
     }
 #endif
 
diff --git a/cogl/cogl/gl-prototypes/cogl-core-functions.h b/cogl/cogl/gl-prototypes/cogl-core-functions.h
index 2fce643a5..0236096c5 100644
--- a/cogl/cogl/gl-prototypes/cogl-core-functions.h
+++ b/cogl/cogl/gl-prototypes/cogl-core-functions.h
@@ -70,8 +70,6 @@ COGL_EXT_FUNCTION (void, glBindBuffer,
                     GLuint              buffer))
 COGL_EXT_FUNCTION (void, glBindTexture,
                    (GLenum target, GLuint texture))
-COGL_EXT_FUNCTION (void, glBlendFunc,
-                   (GLenum sfactor, GLenum dfactor))
 COGL_EXT_FUNCTION (void, glBufferData,
                    (GLenum              target,
                     GLsizeiptr          size,