Add command buffer support for GL_EXT_texture_sRGB_decode

gpu/command_buffer/build_gles2_cmd_buffer.py

Index: gpu/command_buffer/build_gles2_cmd_buffer.py
diff --git a/gpu/command_buffer/build_gles2_cmd_buffer.py b/gpu/command_buffer/build_gles2_cmd_buffer.py
index 5d743ee1a324cd32189e1b26f802cc4d44f7c6db..d6b44762a373ca687089649747a7bc2b944851bc 100755
--- a/gpu/command_buffer/build_gles2_cmd_buffer.py
+++ b/gpu/command_buffer/build_gles2_cmd_buffer.py
@@ -1539,6 +1539,14 @@ _NAMED_TYPE_INFO = {
       'GL_COMPARE_REF_TO_TEXTURE',
     ],
   },
+  'TextureSrgbDecodeExt': {
+    'type': 'GLenum',
+    'is_complete': True,
+    'valid': [
+      'GL_DECODE_EXT',
+      'GL_SKIP_DECODE_EXT',
+    ],
+  },
   'TextureSwizzle': {
     'type': 'GLenum',
     'is_complete': True,