gpu: enable FRAMBUFFER_SRGB on desktop

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 76494a6c8b24f168cf6cd084ba470bf900a8b668..2cd652f79fef32f0a25ffe7b2305c0a71b39ce0f 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -177,7 +177,7 @@ FeatureInfo::FeatureFlags::FeatureFlags()
       emulate_primitive_restart_fixed_index(false),
       ext_render_buffer_format_bgra8888(false),
       ext_multisample_compatibility(false),
-      ext_blend_func_extended(false) {}
+      ext_framebuffer_srgb(false) {}
 
 FeatureInfo::Workarounds::Workarounds() :
 #define GPU_OP(type, name) name(false),
@@ -1188,6 +1188,13 @@ void FeatureInfo::InitializeFeatures() {
   }
   UMA_HISTOGRAM_BOOLEAN("GPU.TextureRG", feature_flags_.ext_texture_rg);
 
+  if (extensions.Contains("GL_ARB_framebuffer_sRGB") ||
+      extensions.Contains("GLX_ARB_framebuffer_sRGB") ||
+      extensions.Contains("WGL_ARB_framebuffer_sRGB")) {
+    feature_flags_.ext_framebuffer_srgb = true;
+    AddExtensionString("GL_ARB_framebuffer_sRGB");
+  }
+
   bool has_opengl_dual_source_blending =
       gl_version_info_->IsAtLeastGL(3, 3) ||
       (gl_version_info_->IsAtLeastGL(3, 2) &&