Disable WebGL texture_rg tests on all OpenGL ES.

BUG=angleproject:1523
BUG=779346

Change-Id: I019597bea3f17f178d584b8a6f070d0640511781
Reviewed-on: https://chromium-review.googlesource.com/743852
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/tests/gl_tests/WebGLCompatibilityTest.cpp b/src/tests/gl_tests/WebGLCompatibilityTest.cpp
index fa84091..a024b2c 100644
--- a/src/tests/gl_tests/WebGLCompatibilityTest.cpp
+++ b/src/tests/gl_tests/WebGLCompatibilityTest.cpp
@@ -3592,7 +3592,7 @@
     EXPECT_GL_ERROR(GL_INVALID_ENUM);
 
     // Verify formats from enableable extensions.
-    if (!IsAndroid())
+    if (!IsOpenGLES())
     {
         validateTexImageExtensionFormat(GL_RED_EXT, "GL_EXT_texture_rg");
     }