WebGLCompatibility: Disable ES format extensions by default.

Prevents format validation errors with WebGL context.

BUG=angleproject:1523

Change-Id: Iddc525eeb467de0139e166dad0893f3bea3ef35f
Reviewed-on: https://chromium-review.googlesource.com/650807
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/tests/gl_tests/CopyTextureTest.cpp b/src/tests/gl_tests/CopyTextureTest.cpp
index 0097ca9..903b80d 100644
--- a/src/tests/gl_tests/CopyTextureTest.cpp
+++ b/src/tests/gl_tests/CopyTextureTest.cpp
@@ -256,10 +256,8 @@
 // Test to ensure that the destination texture is redefined if the properties are different.
 TEST_P(CopyTextureTest, RedefineDestinationTexture)
 {
-    if (!checkExtensions())
-    {
-        return;
-    }
+    ANGLE_SKIP_TEST_IF(!checkExtensions());
+    ANGLE_SKIP_TEST_IF(!extensionEnabled("GL_EXT_texture_format_BGRA8888"));
 
     GLColor pixels[4] = {GLColor::red, GLColor::red, GLColor::red, GLColor::red};