Implement WEBGL_compressed_texture_es3_0 extension for WebGL 1/2

gpu/command_buffer/service/feature_info.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/feature_info.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <vector>
@@ skipping 994 matching lines @@
     validators_.g_l_state.AddValue(GL_TEXTURE_BINDING_EXTERNAL_OES);
   }
 
   if (extensions.Contains("GL_OES_compressed_ETC1_RGB8_texture")) {
     AddExtensionString("GL_OES_compressed_ETC1_RGB8_texture");
     feature_flags_.oes_compressed_etc1_rgb8_texture = true;
     validators_.compressed_texture_format.AddValue(GL_ETC1_RGB8_OES);
     validators_.texture_internal_format_storage.AddValue(GL_ETC1_RGB8_OES);
   }
 
+  // TODO(kainino): Once we have a way to query whether ANGLE is exposing
+  // native support for ETC2 textures, require that here.
+  if (gl_version_info_->is_es3) {
+    AddExtensionString("GL_CHROMIUM_compressed_texture_es3_0");
+    validators_.UpdateES30CompressedTextureFormats();
+  }
+
   if (extensions.Contains("GL_AMD_compressed_ATC_texture")) {
     AddExtensionString("GL_AMD_compressed_ATC_texture");
     validators_.compressed_texture_format.AddValue(
         GL_ATC_RGB_AMD);
     validators_.compressed_texture_format.AddValue(
         GL_ATC_RGBA_EXPLICIT_ALPHA_AMD);
     validators_.compressed_texture_format.AddValue(
         GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD);
 
     validators_.texture_internal_format_storage.AddValue(
@@ skipping 500 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu