Revert "Expose GL_CHROMIUM_compressed_texture_etc when ANGLE supports it."

This reverts commit 2d170801.

Reason for revert: might have broken angle_perftests https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20FYI%20Release%20%28NVIDIA%29/6461

Original change's description:
> Expose GL_CHROMIUM_compressed_texture_etc when ANGLE supports it.
> 
> ANGLE now exposes this extension under the same conditions as Chrome: on top
> of a native ES driver.
> 
> BUG=angleproject:1552
> 
> Change-Id: I6552e51bccd5ece43b7405b26d63127283a90c46
> Reviewed-on: https://chromium-review.googlesource.com/c/1342497
> Reviewed-by: Zhenyao Mo <zmo@chromium.org>
> Reviewed-by: Kai Ninomiya <kainino@chromium.org>
> Commit-Queue: Geoff Lang <geofflang@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#609713}

TBR=zmo@chromium.org,geofflang@chromium.org,kainino@chromium.org

Change-Id: I92f0b2e98577af73cd23510e95868d29ac04e775
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: angleproject:1552
Reviewed-on: https://chromium-review.googlesource.com/c/1344582Reviewed-by: Saman Sami <samans@chromium.org>
Commit-Queue: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609758}

gpu/command_buffer/service/feature_info.cc

@@ -1029,11 +1029,10 @@ void FeatureInfo::InitializeFeatures() {
     validators_.texture_internal_format_storage.AddValue(GL_ETC1_RGB8_OES);
   }
 
-  // Expose GL_CHROMIUM_compressed_texture_etc when ANGLE exposes it directly or
-  // running on top of a non-ANGLE ES driver. We assume that this implies native
-  // support of these formats.
-  if (gfx::HasExtension(extensions, "GL_CHROMIUM_compressed_texture_etc") ||
-      (gl_version_info_->is_es3 && !gl_version_info_->is_angle)) {
+  // TODO(kainino): Once we have a way to query whether ANGLE is exposing
+  // native support for ETC2 textures, require that here.
+  // http://anglebug.com/1552
+  if (gl_version_info_->is_es3 && !gl_version_info_->is_angle) {
     AddExtensionString("GL_CHROMIUM_compressed_texture_etc");
     validators_.UpdateETCCompressedTextureFormats();
   }

third_party/blink/renderer/modules/webgl/webgl_compressed_texture_etc.cc

@@ -11,8 +11,6 @@ namespace blink {
 WebGLCompressedTextureETC::WebGLCompressedTextureETC(
     WebGLRenderingContextBase* context)
     : WebGLExtension(context) {
-  context->ExtensionsUtil()->EnsureExtensionEnabled(
-      "GL_CHROMIUM_compressed_texture_etc");
   context->AddCompressedTextureFormat(GL_COMPRESSED_R11_EAC);
   context->AddCompressedTextureFormat(GL_COMPRESSED_SIGNED_R11_EAC);
   context->AddCompressedTextureFormat(GL_COMPRESSED_RGB8_ETC2);