SRGB_EXT is a valid format of texture in WebGL1.0 and ES2.0 contexts

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 593 matching lines @@
        extensions.Contains("GL_EXT_sRGB")) ||
       gfx::HasDesktopGLFeatures()) {
     AddExtensionString("GL_EXT_sRGB");
     validators_.texture_internal_format.AddValue(GL_SRGB_EXT);
     validators_.texture_internal_format.AddValue(GL_SRGB_ALPHA_EXT);
     validators_.texture_format.AddValue(GL_SRGB_EXT);
     validators_.texture_format.AddValue(GL_SRGB_ALPHA_EXT);
     validators_.render_buffer_format.AddValue(GL_SRGB8_ALPHA8_EXT);
     validators_.frame_buffer_parameter.AddValue(
         GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING_EXT);
+    validators_.texture_unsized_internal_format.AddValue(GL_SRGB_EXT);

[Ken Russell (switch to Gerrit), 2016/04/24 15:57:22]

One point. This should only be added for ES 2.0 + the EXT_srgb extension. If the
context is for ES 3.0 / WebGL 2.0, GL_SRGB (which was promoted to core in ES
3.0) is not a valid internal format. Only the sized internal formats GL_SRGB8
and GL_SRGB8_ALPHA8 are valid. Can you please figure out how to add this
constraint? Can you also please extend the WebGL 2.0 conformance tests to make
sure that GL_SRGB is tested as an invalid internal format, if it isn't being
already? Thanks.

[Zhenyao Mo, 2016/04/25 18:00:00]

Right.  This is an issue existing before this CL. We should only expose   this
extension if the context_type_ is WEBGL1 or ES2.

Then on ES3 and Desktop, in Tex{Sub}Image handling, we need to map SRGB and
SRGB_ALPHA to SRGB8 and SRGB8_ALPHA8.

     validators_.texture_unsized_internal_format.AddValue(GL_SRGB_ALPHA_EXT);
   }
 
   bool enable_texture_format_bgra8888 = false;
   bool enable_read_format_bgra = false;
   bool enable_render_buffer_bgra = false;
   bool enable_immutable_texture_format_bgra_on_es3 =
       extensions.Contains("GL_APPLE_texture_format_BGRA8888");
 
   // Check if we should allow GL_EXT_texture_format_BGRA8888
@@ skipping 800 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu