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

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 58aa147c2a3e0a9dac15e9063ee17f7580049d46..d66c91e3149dc76e4b4c90bfb8b5927474f32326 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -611,6 +611,7 @@ void FeatureInfo::InitializeFeatures() {
     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);

[yunchao, 2016/04/12 07:21:34]

This ext has been added into texture_internal_format and texture_format. Why it
needs to be added into texture_unsized_internal_format? Is there any test case? 

[qiankun, 2016/04/12 11:01:50]

GLES extension spec can be found at
https://www.khronos.org/registry/gles/extensions/EXT/EXT_sRGB.txt. It is based
on gles2: 
"Modify Section 3.7.1, Texture Image Specification:

    Add 2 new rows to Table 3.3

        SRGB_EXT             R, G, B        Color
        SRGB_ALPHA_EXT       R, G, B, A     Color

    Add 2 new rows to Table 3.4
    
        SRGB_EXT           UNSIGNED_BYTE     3
        SRGB_ALPHA_EXT     UNSIGNED_BYTE     4
"
So map to gles3, SRGB_EXT should be added to table 3.3 in
https://www.khronos.org/registry/gles/specs/3.0/es_spec_3.0.4.pdf.

     validators_.texture_unsized_internal_format.AddValue(GL_SRGB_ALPHA_EXT);
   }