gpu: Clarify sized texture format is available only if ES3 context or immutable texture is supported

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 1004 matching lines @@
   if (extensions.Contains("GL_ANGLE_texture_usage")) {
     feature_flags_.angle_texture_usage = true;
     AddExtensionString("GL_ANGLE_texture_usage");
     validators_.texture_parameter.AddValue(GL_TEXTURE_USAGE_ANGLE);
   }
 
   if (enable_texture_storage) {
     feature_flags_.ext_texture_storage = true;
     AddExtensionString("GL_EXT_texture_storage");
     validators_.texture_parameter.AddValue(GL_TEXTURE_IMMUTABLE_FORMAT_EXT);
-    if (enable_texture_format_bgra8888)
+    if (enable_texture_format_bgra8888) {
+        validators_.texture_internal_format.AddValue(GL_BGRA8_EXT);
         validators_.texture_internal_format_storage.AddValue(GL_BGRA8_EXT);
+        validators_.texture_sized_color_renderable_internal_format.AddValue(
+            GL_BGRA8_EXT);
+    }
     if (enable_texture_float) {
         validators_.texture_internal_format_storage.AddValue(GL_RGBA32F_EXT);
         validators_.texture_internal_format_storage.AddValue(GL_RGB32F_EXT);
         validators_.texture_internal_format_storage.AddValue(GL_ALPHA32F_EXT);
         validators_.texture_internal_format_storage.AddValue(
             GL_LUMINANCE32F_EXT);
         validators_.texture_internal_format_storage.AddValue(
             GL_LUMINANCE_ALPHA32F_EXT);
     }
     if (enable_texture_half_float) {
@@ skipping 375 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu