Add hooks for GL_EXT_debug_markers for Skia

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 64b0ee48d521e9a318a447307f40b52c37128c5a..9803816a13e272f00cb606e6d0e9be7ac6a39306 100644
--- a/gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc
+++ b/gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc
@@ -70,9 +70,12 @@ GrGLInterface* CreateCommandBufferSkiaGLBinding() {
   functions->fGetShaderiv = glGetShaderiv;
   functions->fGetString = glGetString;
   functions->fGetUniformLocation = glGetUniformLocation;
+  functions->fInsertEventMarker = glInsertEventMarkerEXT;
   functions->fLineWidth = glLineWidth;
   functions->fLinkProgram = glLinkProgram;
   functions->fPixelStorei = glPixelStorei;
+  functions->fPopGroupMarker = glPopGroupMarkerEXT;
+  functions->fPushGroupMarker = glPushGroupMarkerEXT;
   functions->fReadPixels = glReadPixels;
   functions->fScissor = glScissor;
   functions->fShaderSource = glShaderSource;