Add support for OES_EGL_image_external and OES_EGL_image_external_essl3.

BUG=angleproject:1372

Change-Id: I8489e7fd0ab409b0775041ad5e9fbf0aab53886d
Reviewed-on: https://chromium-review.googlesource.com/344734
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
diff --git a/src/compiler/translator/TextureFunctionHLSL.cpp b/src/compiler/translator/TextureFunctionHLSL.cpp
index b859310..f0b48d0 100644
--- a/src/compiler/translator/TextureFunctionHLSL.cpp
+++ b/src/compiler/translator/TextureFunctionHLSL.cpp
@@ -201,6 +201,7 @@
         switch (textureFunction.sampler)
         {
             case EbtSampler2D:
+            case EbtSamplerExternalOES:
                 hlslCoords = 2;
                 break;
             case EbtSamplerCube:
@@ -275,6 +276,7 @@
         switch (textureFunction.sampler)
         {
             case EbtSampler2D:
+            case EbtSamplerExternalOES:
                 out << "sampler2D s";
                 break;
             case EbtSamplerCube:
@@ -790,6 +792,7 @@
         switch (textureFunction.sampler)
         {
             case EbtSampler2D:
+            case EbtSamplerExternalOES:
                 out << "tex2D";
                 break;
             case EbtSamplerCube: