Revert of Support using OpenGL ES context on desktop (https://codereview.chromium.org/319043005/)

Reason for revert:
Caused segmentation fault on many builders. Please see reverted CL's msg #21 for details.

Original issue's description:
> Support using OpenGL ES context on desktop
>
> Support using OpenGL ES context on desktop for unix and Android platforms. This
> is mainly useful in development.
>
> Add --gpuAPI flag to gm, dm, bench, bench_pictures and render_pictures. The
> possible parameters for the flag are "gl" and "gles".
>
> Committed: https://skia.googlesource.com/skia/+/74fc727dc88ee24d89f88cb1709f963e9073aeb3

R=bsalomon@google.com, mtklein@google.com, robertphillips@google.com, kkinnunen@nvidia.com
TBR=bsalomon@google.com, kkinnunen@nvidia.com
NOTREECHECKS=true
NOTRY=true

Author: rmistry@google.com

Review URL: https://codereview.chromium.org/351583002
diff --git a/experimental/PdfViewer/pdf_viewer_main.cpp b/experimental/PdfViewer/pdf_viewer_main.cpp
index c1b0284..2f1a055 100644
--- a/experimental/PdfViewer/pdf_viewer_main.cpp
+++ b/experimental/PdfViewer/pdf_viewer_main.cpp
@@ -168,8 +168,7 @@
 #if SK_SUPPORT_GPU
         else if (strcmp(FLAGS_config[0], "gpu") == 0) {
             SkAutoTUnref<GrSurface> target;
-            GrContext* gr = gContextFactory.get(GrContextFactory::kNative_GLContextType,
-                                                kNone_GrGLStandard);
+            GrContext* gr = gContextFactory.get(GrContextFactory::kNative_GLContextType);
             if (gr) {
                 // create a render target to back the device
                 GrTextureDesc desc;