Add glBlendEquation to skia GL bindings

gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc

Index: gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc
diff --git a/gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc b/gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc
index 1e997ba70ce10752b9565ab08434a74cbb792dff..c8cc36cdb70ccc0ee246a07781f7de7b9a63f9b2 100644
--- a/gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc
+++ b/gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc
@@ -30,6 +30,7 @@ GrGLInterface* CreateCommandBufferSkiaGLBinding() {
   functions->fBindTexture = glBindTexture;
   functions->fBindVertexArray = glBindVertexArrayOES;
   functions->fBlendColor = glBlendColor;
+  functions->fBlendEquation = glBlendEquation;
   functions->fBlendFunc = glBlendFunc;
   functions->fBufferData = glBufferData;
   functions->fBufferSubData = glBufferSubData;