Add GL_CHROMIUM_screen_space_antialiasing to support alternative AA

gpu/command_buffer/service/gles2_cmd_decoder_autogen.h

 // Copyright 2014 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.
 
 // This file is auto-generated from
 // gpu/command_buffer/build_gles2_cmd_buffer.py
 // It's formatted by clang-format using chromium coding style:
 //    clang-format -i -style=chromium filename
 // DO NOT EDIT!
 
@@ skipping 5048 matching lines @@
   if (!features().blend_equation_advanced) {
     LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, "glBlendBarrierKHR",
                        "function not available");
     return error::kNoError;
   }
 
   glBlendBarrierKHR();
   return error::kNoError;
 }
 
+error::Error GLES2DecoderImpl::HandleApplyScreenSpaceAntialiasingCHROMIUM(
+    uint32_t immediate_data_size,
+    const void* cmd_data) {
+  const gles2::cmds::ApplyScreenSpaceAntialiasingCHROMIUM& c =
+      *static_cast<const gles2::cmds::ApplyScreenSpaceAntialiasingCHROMIUM*>(
+          cmd_data);
+  (void)c;
+  if (!features().chromium_screen_space_antialiasing) {
+    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
+                       "glApplyScreenSpaceAntialiasingCHROMIUM",
+                       "function not available");
+    return error::kNoError;
+  }
+
+  DoApplyScreenSpaceAntialiasingCHROMIUM();
+  return error::kNoError;
+}
+
 bool GLES2DecoderImpl::SetCapabilityState(GLenum cap, bool enabled) {
   switch (cap) {
     case GL_BLEND:
       state_.enable_flags.blend = enabled;
       if (state_.enable_flags.cached_blend != enabled ||
           state_.ignore_cached_state) {
         state_.enable_flags.cached_blend = enabled;
         return true;
       }
       return false;
@@ skipping 74 matching lines @@
         state_.enable_flags.cached_primitive_restart_fixed_index = enabled;
         return true;
       }
       return false;
     default:
       NOTREACHED();
       return false;
   }
 }
 #endif  // GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_AUTOGEN_H_