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

gpu/command_buffer/service/feature_info.cc

Index: gpu/command_buffer/service/feature_info.cc
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index dafa6caccd71a3c2772943f7ecc79212d51b26f4..032d1d4849e9faffc7bb60a2a48181a9a476bdad 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -1022,8 +1022,12 @@ void FeatureInfo::InitializeFeatures() {
     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);